Portable lighting devices

ABSTRACT

A flashlight has a lock out feature that prevents it from being turned on which is activated or deactivated by pointing the flashlight in a first direction (e.g., upward) prior to turning it on, depressing a switch to turn it on, tilting the flashlight in a second direction (e.g., downward) while continuously depressing the switch, and releasing the switch.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. Ser. No.12/657,290, the disclosure of which is incorporated by reference as iffully set forth herein. U.S. Ser. No. 12/657,290 was based on andclaimed priority to U.S. Provisional Application Ser. No. 61/145,120,filed Jan. 16, 2009, the disclosure of which is incorporated byreference as if fully set forth herein. U.S. Ser. No. 12/657,290 wasalso a continuation-in-part, and was based on and claimed priority toU.S. application Ser. No. 12/505,555, filed Jul. 20, 2009, which in turnwas a continuation-in-part of U.S. application Ser. No. 12/502,237,filed Jul. 14, 2009, the disclosures of all of which are incorporated byreference as if fully set forth herein.

TECHNICAL FIELD

The current inventions generally relate to the field of portablelighting devices, including for example, flashlights, lanterns andheadlamps, and their circuitry.

BACKGROUND

Various hand held or portable lighting devices, including flashlights,are known in the art. Such lighting devices typically include one ormore dry cell batteries having positive and negative electrodes. Thebatteries are arranged electrically in series or parallel in a batterycompartment or housing. The battery compartment also sometimes functionsas the handle for the lighting device, particularly in the case offlashlights where a barrel contains the batteries and is also used tohold the flashlight. An electrical circuit is established from a batteryelectrode through conductive means which are electrically coupled withan electrode of a light source, such as a lamp bulb or a light emittingdiode (“LED”). After passing through the light source, the electriccircuit continues through a second electrode of the light source inelectrical contact with conductive means, which in turn are inelectrical contact with the other electrode of a battery. The circuitincludes a switch to open or close the circuit. Actuation of the switchto close the electrical circuit enables current to pass through the lampbulb, LED, or other light source—and through the filament, in the caseof an incandescent lamp bulb—thereby generating light.

Some advanced portable lighting devices provide multiple modes ofoperation for different needs. For example, in addition to the normal“full power” or “standard power” mode, a power reduction mode, blinkmode and/or an SOS mode have been implemented in portable lightingdevices, such as flashlights. In such portable lighting devices, theuser typically elects the desired mode of operation by manipulation of auser interface, typically a main switch. For example, when the portablelighting device is in the normal mode or the power save mode ofoperation, the portable lighting device may be transitioned to anothermode of operation, such as an SOS mode, by manipulating the main switchto momentarily turn “off” and then turn back “on” the portable lightingdevice. In other devices, the main switch may be required to bedepressed and held a certain period of time to cause the lighting deviceto index to the next operational mode. Portable lighting devices thatinclude advanced functionality may include an electronic power switchcontrolled by a microcontroller or microprocessor to provide the desiredfunctionality.

One potential problem of the portable lighting devices with multiplefunctions described above is that a user needs to manipulate the mainswitch in some manner in order to enter into a new mode of operation. Ifthe main switch is located on the barrel of, for example, a flashlight,the sequence of pushing and releasing the main switch may cause theflashlight under operation to point away from the area of intendedillumination.

Another problem associated with the use of the main switch as the userinterface to enter a new mode of operation is that the requiredmanipulation sequence is often complicated or simply takes too long toindex through the different modes of operation. Yet another problemassociated with the main switch approach is that the frequentmanipulation of the main switch to index through the different modes ofoperation may cause the mechanical parts of the switch to prematurelywear out, shortening the useful life of the portable lighting device.

Accordingly, a need exists for a portable lighting device with animproved user interface that does not require the repeated orcomplicated manipulation of a mechanical switch to index through thevarious modes of operation that the portable lighting device mayprovide.

Flashlights and other portable lighting devices have conventionallyemployed a mechanical power switch in the main power circuit of theflashlight to turn “on” and turn “off” the portable lighting device.When the user turns “on” the portable lighting device, the usertypically presses down or otherwise manipulates the mechanical powerswitch to mechanically connect two contacts to close the switch andcomplete the power circuit, thereby allowing current to flow from thepositive terminal of the batteries, through the light source and to thenegative terminal of the batteries. When the user turns “off” theportable lighting device, the user again manipulates the mechanicalswitch to disconnect the two contacts of the switch and thereby open theswitch and break the power circuit. The mechanical power circuit in suchdevices, therefore, acts as a conductor in completing the power circuit,and thus conducts current throughout the operation of the portablelighting device.

Because mechanical power switches form part of the circuit of thelighting device, the contacts of such switches tend to be fairly heavyduty. Accordingly, such switches tend to require a significant amount offorce in order to close and open their contacts. As a result, using aportable lighting device having a mechanical power switch as a signalingdevice over a prolonged period may be difficult. For example, the forcerequired to manipulate the switch between the “on” and “off” positionsmay fatigue the user after a prolonged period of using the portablelighting device in a signaling application. Further, with somemechanical power switches, it may simply take too much time to close andopen the mechanical power switch in order to turn “on” and “off” theportable lighting device to perform certain signaling applications.

Another problem with using the portable lighting device's main switch toimplement a user implemented signaling mode is that the repeatedmanipulation of the main switch to turn “off” and then turn back “on”the lighting device may cause the mechanical parts of the switch toprematurely wear out, shortening the life of the lighting device.

Some switches employed in portable electronic lighting devices mayrequire less force to manipulate because they typically do not form partof the main power circuit of the lighting device and are thus not asheavy duty. While this is potentially beneficial from a user fatiguestandpoint in a signaling application, multi-mode portable electronicdevices present their own set of problems for user implemented signalingmodes.

For example, in multi-mode electronic portable lighting devices, thevarious modes of operation may be selected by a user turning off thelighting device for less than a predetermined period of time, such as 1to 2 seconds, and then turning the lighting device back on again. Inresponse to this short turn off period, the lighting device indexes tothe next mode.

It would therefore be difficult to use a multi-mode portable electroniclighting device configured in this manner for a user implementedsignaling mode. This is because the user must wait more than thepredetermined period of time before turning the lighting device back on,otherwise it will automatically index to the next mode of operation,thereby interfering with the user's intended signaling operation. Inother words, the user would be precluded from signaling with shortalternating periods of light and no light to communicate through, forexample, Morse code.

Accordingly, a need exists for an improved portable electronic lightingdevice that may be used in a user implemented signaling mode without themanipulation of a mechanical switch to repeatedly turn the lightingdevice “on” and “off.”

A compass is useful in a variety of outdoor sports or hobbies,including, for example, backpacking, hiking, mountain climbing, boating,etc. A traditional magnetic compass includes a magnetized needle toindicate the direction of the Earth's magnetic north. In the dark,however, the direction in which the magnetized needle is pointing may behard to see without the assistance of a light source. In some compasses,the needle and portions of the compass face are coated with afluorescent material to improve night viewing and use. In very darkconditions, however, such fluorescent coatings may be inadequate. Someadvanced compasses are provided with a built-in light source to beturned on when desired. Such compasses, however, tend to be moreexpensive and are more likely to be owned by a smaller group of trueoutdoor enthusiasts. Further, many situations arise where individualswould benefit from having a compass, but for a variety of reasons simplydo not have a compass, although they do have a flashlight or otherportable lighting device in their possession.

Accordingly, a need exists for a portable lighting device, such as aflashlight or headlamp, that provides a compass function. It would bebeneficial if the device could be used both during the day and thenight. Such a device would be useful to a broad class of individuals,including the outdoor enthusiast, as well as the outdoor novice.

Night lights that plug into the wall are conventionally known. Thesenight lights are not portable, however, thus making a night lightrequired in multiple rooms to provide adequate safety. Some individualsuse flashlights or other portable lighting devices as an alternative orin addition to the conventional wall plug-in nightlights. However, if aconventional flashlight or portable lighting device is left on overnight to provide constant light, the batteries of the lighting devicemay be quickly drained.

Alternatively, if the portable lighting device is turned off to savebattery power, locating the lighting device in the dark can beproblematic. In some situations it could even lead to injury,particularly in emergency situations, as the user searches for theportable lighting device.

Accordingly, a need exists for a portable lighting device that hasimproved functionality as a night light.

In multi-mode portable electronic lighting devices, the electronics ofthe lighting device may include a number of preprogrammed functions.Such modes may include a “standard power” mode, power reduction mode, ablink mode and an SOS mode. The various individual modes of suchconventional multi-mode devices, however, cannot be adjusted. As aresult, the user of the portable lighting device must simply select theparticular mode of operation that best fits his or her needs.

One approach to solving this problem has been to program additionalmodes of operation into the lighting device. For example, instead ofhaving a single power reduction mode, the portable lighting device maybe provided with two discrete power reduction modes, such as a 75% powerreduction mode and a 50% power reduction mode. This discrete approach tothe problem may not be very practical, however, because as each new modeof operation is added to the portable lighting device, more time isrequired to index through the different discrete modes of operation,thus making it less likely that a user will even use the advancedfunctionality of the lighting device. A user interface, such as a singleswitch, also does not provide a practical option for including a numberof modes of operation. Indeed, for some designs, it would be cumbersometo attempt to access over, for example, four or five discrete modes ofoperation.

Accordingly, a need exists for a multi-mode portable lighting devicethat enables user adjustable modes of operation.

When a portable lighting device, such as a flashlight or headlamp, isturned on, battery power is consumed. As a result, if the lightingdevice is left “on” inadvertently, battery power, or battery life in thecase of dry-cell batteries, may be wasted. This unfortunately may renderthe portable lighting device useless or of decreased performance when itmay actually be needed. To mitigate this issue, some portable lightingdevices have been provided with an auto-off feature, which automaticallyturns the lighting device off after a predetermined period of time haslapsed, implemented in this fashion, however, an auto-off feature can bedangerous because the portable lighting device may automatically turn“off” when the user still requires illumination from the lightingdevice.

Accordingly, a need exists for a portable lighting device with animproved auto-off feature.

Because modern portable electronic lighting devices typically employswitches that require less force to activate than flashlights employingconventional mechanical power switches, such electronic lighting devicesmay be susceptible to being inadvertently turned “on” during storage.This can lead to complete battery drainage. While some portableelectronic lighting devices are provided with an auto-off feature asnoted above, this is not a completely satisfactory solution to theforegoing problem because some battery power will be lost before thelighting device is automatically turned off. Furthermore, if theportable lighting device is again jostled in a manner to cause the mainswitch to activate the lighting device, the lighting device may again beturned “on” until the auto off feature again turns the device off,resulting in additional battery drain.

Accordingly, a need exists for an improved portable electronic lightingdevice that can reduce the likelihood that the lighting device will beinadvertently turned “on.”

In many existing portable lighting devices, the batteries are containedin the device's housing, e.g., the flashlight barrel. In the case ofrechargeable flashlights, the rechargeable battery(ies) may be containedin a battery pack. Other attempts have been made to create battery packsor cassettes that contain all the batteries used to power the lightingdevice, in order to allow easy insertion and removal of the batteriesall at once. However, such battery packs and cassettes often comprise ahousing that requires multiple threaded fasteners to assemble, resultingin a complicated and costly battery pack or cassette. Further, in thecase of rechargeable battery packs, if any electronics are used inconnection with recharging, the electronics may not be contained in thebattery pack. Accordingly, extra connections are typically required thatmay increase manufacturing cost and design complexity.

Accordingly, there is a need for improved battery packs in both thenon-rechargeable and rechargeable contexts.

SUMMARY

A number of portable lighting devices and methods of operating same areprovided. In general, the portable lighting devices may be any type ofportable lighting device, including, for example, flashlights,headlamps, lanterns, etc.

As an example, a portable lighting device configured to operate using aportable source of power is provided in which the portable lightingdevice comprises a main power circuit, an inertial sensor and acontroller. The main power circuit includes a light source, anelectronic power switch, and is configured to electrically connect thelight source to the portable source of power. The inertial sensor has atleast one signal output. The controller is electrically connected to theelectronic power switch in a manner to permit the controller to controlthe flow of power through the electronic power switch and light sourcein the main power circuit. The controller is also electrically connectedto at least one output from the inertial sensor. The controller isprogrammed to control the flow of power through the light source basedon one or more signals received from at least one output of the inertialsensor. In addition, for example, the controller may be programmed toenter into a new mode of operation based on input received from at leastone output of the inertial sensor.

One potential method of operating a portable lighting device, such as aflashlight or headlamp, involves moving the lighting device in a firstpredetermined manner to cause the lighting device to enter a new mode ofoperation. The method may further include moving the lighting device ina second predetermined direction to adjust the mode of operation. Forexample, the portable lighting device may be rotated in a firstdirection about a principal axis of projection of the light source tocause it to enter a new mode of operation. Further, rotation about theprincipal axis of projection in the opposite direction may be used toadjust a selected mode. The above methods are advantageous in that a newmode of operation may be selected without a press and release sequencesof the main switch. Likewise, the methods will also enable theadjustment of a selected mode without implementing a complicated pressand release sequence of the main switch. The movement in the first andsecond predetermined manners may also comprise movements other thanrotating around the principal axis of projection. For example, they maycomprise a certain shaking sequence.

As an example, a portable lighting device configured to operate using aportable source of power is provided in which the portable lightingdevice comprises a main power circuit, a magnetic sensor and acontroller. The main power circuit includes a light source and anelectronic switch and is configured to electrically connect the lightsource to the portable source of power. The magnetic sensor has at leastone signal output. The controller is also electrically connected to theelectronic power switch in a manner to permit the controller to controlthe flow of power through the electronic power switch and light sourcein the main power circuit. The controller is also electrically connectedto at least one output from the magnetic sensor, wherein the controlleris configured to output a control signal based on input received from atleast one output of the magnetic sensor. In one embodiment, the controlsignal is communicated to the electronic switch to control the flow ofpower through the light source and generate a predetermined visualresponse. In another embodiment, the control signal is communicated toan audio device to generate a predetermined audio response. Yet inanother embodiment, the control signal is communicated to an electricmotor to generate a predetermined vibrating response. A differentcommand signal may be generated as a coordinate marker on the lightingdevice is rotated to align with different cardinal coordinates so as tocause a different visual, audible, or vibrating response by the lightsource or audio device, respectively. In one embodiment, the coordinatemarker comprises a principal axis of projection of the light source ofthe portable lighting device. In other embodiments, the coordinatemarker comprises a physical mark on an exterior portion of the portablelighting device.

One potential method of operating a portable lighting device, such as aflashlight having a compass feature, may involve rotating the portablelighting device around an axis of rotation that is substantially normalto a coordinate marker of the lighting device to cause the flashlight orportable lighting device to output a visual, audio and/or vibratingresponse when the coordinate marker of the lighting device is facingtoward the Earth's magnetic north pole. In one embodiment, thecoordinate marker comprises a principal axis of projection of the lightsource. In another embodiment, the coordinate marker comprises aphysical mark on an exterior portion of the portable lighting device.

In one embodiment, the lighting device becomes incrementally brighter asthe coordinate marker is rotated toward the Earth's magnetic north poleand turns incrementally dimmer as the coordinate marker is rotated awayfrom the Earth's magnetic north pole toward the Earth's magnetic southpole. Therefore, the portable lighting device is able to provide thefunction of a compass by providing different visual responses based onthe light source when the flashlight or portable lighting device ispointing toward different direction.

As an example, the brightness of the light source can be increased whenthe flashlight or portable lighting device is facing forward themagnetic north coordinates of the Earth and the light source providesthe brightest light when the flashlight or portable lighting device isfacing at the magnetic north coordinates of the Earth.

As an example, the light source produces a blink signal when theprincipal axis of projection of the flashlight or portable lightingdevice is within a 5° angle of one of the magnetic cardinal coordinatesof the Earth.

As an example, a portable lighting device can be configured to operateusing a portable source of power, the portable lighting devicecomprising a main power circuit including a light source, an inertialsensor, and a controller. The main power circuit can be configured toelectrically connect the light source to the portable source of power.The inertial sensor can have a plurality of signal outputs. Thecontroller can be electrically connected to the main power circuit in amanner to permit the controller to control the flow of power through thelight source in the main power circuit. The controller can also beelectrically connected to the outputs of the inertial sensor, whereinthe controller is programmed to control the flow of power through thelight source in a variety of levels based on signals received from theoutputs of the inertial sensor.

One potential method of operating a flashlight or a portable lightingdevice is by rotating the flashlight or portable lighting device right(or left depending on the user configuration) along the principal axisof projection of the light source to turn the flashlight or portablelighting device on while by rotating the flashlight or a portablelighting device left (or right depending on the user configuration)along the principal axis of projection of the light source to turn theflashlight or portable lighting device off. Therefore, the push buttonis not necessary when the flashlight or portable lighting device isturned on or off.

As another example, one potential method of operating a flashlight or aportable lighting device is by rotating the flashlight or a portablelighting device right (or left depending on the user configuration)along the principal axis of projection of the light source to turn theflashlight or portable lighting device brighter while by rotating theflashlight or portable lighting device left (or right depending on theuser configuration) along the principal axis of projection of the lightsource to turn the flashlight or portable lighting device dimmer.Therefore, a push button is not required when the flashlight or portablelighting device is turned in a variety of brightness.

As another example, one potential method of operating a flashlight or aportable lighting device is by rotating the flashlight or portablelighting device right (or left depending on the user configuration)along the principal axis of projection of the light source to turn theflashlight or portable lighting device in a higher blinking rate whileby rotating the portable lighting device left (or right depending on theuser configuration) along the principal axis of projection of the lightsource to turn the flashlight or portable lighting device in a lowerblinking rate. Therefore, the push button is not necessary when theflashlight or portable lighting device is turned in a variety ofblinking rate.

As an example, a portable lighting device can be configured to operateusing a portable source of power, the portable lighting devicecomprising: a main power circuit including a light source, an inertialsensor, and a controller. The main power circuit can be configured toelectrically connect the light source to the portable source of power.The inertial sensor can have a plurality of signal outputs. Thecontroller can be electrically connected to the main power circuit in amanner to permit the controller to control the flow of power through thelight source in the main power circuit. The controller can also beelectrically connected to the outputs of the inertial sensor, whereinthe controller is programmed to start the flow of power through thelight source based on signals received from the outputs of the inertialsensor.

One potential method of operating a flashlight or portable lightingdevice is by setting the flashlight or portable lighting device in anight light mode so that that when movement is detected by theflashlight or portable lighting device, it automatically becomesbrighter.

As an example, a portable lighting device can be configured to operateusing a portable source of power, the portable lighting devicecomprising: a main power circuit including a light source, an inertialsensor, and a controller. The main power circuit can be configured toelectrically connect the light source to the portable source of power.The inertial sensor can have a plurality of signal outputs. Thecontroller can be electrically connected to the main power circuit in amanner to permit the controller to control the flow of power through thelight source in the main power circuit. The controller also beingelectrically connected to the outputs of the inertial sensor, whereinthe controller stores an adjustable parameter in a memory based onsignals received from the outputs of the inertial sensor.

One potential method of configuration of a flashlight or a portablelighting device is by pointing the flashlight or portable lightingdevice up and rotating the flashlight or portable lighting device rightalong the principal axis of projection of the light source to set theflashlight or portable lighting device to a right-handed configurationwhile by pointing the flashlight or portable lighting device up androtating the portable lighting device left along the principal axis ofprojection of the light source to set the portable lighting device to aleft-handed configuration. Therefore, the flashlight or other portablelighting device can be readily adapted to use by either right orleft-handed users based on a configuration process performed by theuser.

As an example, a portable lighting device can be configured to operateusing a portable source of power, the portable lighting devicecomprising: a main power circuit including a light source, an inertialsensor, and a controller. The main power circuit can be configured toelectrically connect the light source to the portable source of power.The inertial sensor can have a plurality of signal outputs. Thecontroller can be electrically connected to the main power circuit in amanner to permit the controller to control the flow of power through thelight source in the main power circuit. The controller can also beelectrically connected to the outputs of the inertial sensor, whereinthe controller is programmed to stop the flow of power through the lightsource based on signals received from the outputs of the inertialsensor.

One potential method of operating a flashlight or a portable lightingdevice is that when the flashlight or portable lighting device is notmoved for a predefined period of time, it automatically turns off. Asanother example, the auto off feature can be activated or deactivated bya user.

In a further aspect, a rechargeable battery pack is provided. Therechargeable battery pack includes a housing having a front end and rearend, a rechargeable battery located within the housing, a circuit boardlocated within the housing and including front circuit board electricalcontacts, a front end cap assembly mounted at the front end of thehousing and including a plurality of front end cap electrical contactscoupled to the front circuit board electrical contacts, and a rear endcap assembly mounted at the rear end of the housing and including aplurality of rear end cap electrical contacts coupled to the rearcircuit board electrical contacts.

In still another aspect, a rechargeable battery pack is provided thatincludes a housing, a rechargeable battery, and an accelerometer.

In still another aspect, a portable lighting device comprising arechargeable battery pack of the type described above is provided.

In a further aspect, a rechargeable battery pack, including a housing, arechargeable battery, and a magnetron to provide a compass function isprovided.

In a further aspect, a battery cassette is provided, the batterycassette includes a front housing, a rear housing, at least one rearhousing electrical contact that provides a negative electrode at an endof the battery cassette, and a central connector that couples the fronthousing and rear housing, and that provides a positive electrode at bothends of the battery cassette. The plurality of bays are formed when thefront housing and rear housing are joined.

According to another aspect, a portable lighting device comprising abattery cassette is provided.

Further aspects, objects, and desirable features, and advantages of theinvention will be better understood from the following descriptionconsidered in connection with the accompanying drawings in which variousembodiments of the disclosed invention are illustrated by way ofexample. It is to be expressly understood, however, that the drawingsare for the purpose of illustration only and are not intended as adefinition of the limits of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of an exemplary flashlight.

FIG. 2 is a cross-sectional view of the flashlight of FIG. 1 taken alongthe plane indicated by 102-102.

FIG. 3 is an enlarged cross-sectional view of the forward section of theflashlight of FIG. 1 taken through the plane indicated by 102-102.

FIG. 4 is an enlarged cross-sectional view of the rearward section ofthe flashlight of FIG. 1 taken through the plane indicated by 102-102.

FIG. 5A is an exploded perspective view of the head assembly and aportion of the barrel of the flashlight of FIG. 1. FIG. 5B is anexploded perspective view of the switch and tail cap assembly portion ofthe flashlight of FIG. 1.

FIG. 6 is an exploded perspective view of a rechargeable battery pack.

FIG. 7 is a schematic diagram illustrating the internal and externalelectrical connections of the battery pack of FIG. 6.

FIG. 8 is a circuit diagram illustrating the relationship between theelectronic circuitry according to one embodiment of the invention.

FIGS. 9A-G are schematic circuit diagrams of different components of thecircuit shown in FIG. 8.

FIGS. 10A-K are flow diagrams illustrating the operations of aflashlight according to different aspects of the invention.

FIG. 11 is a plan view of another exemplary flashlight.

FIG. 12 is a cross-sectional view of the flashlight of FIG. 11 takenalong the plane indicated by 302-302.

FIG. 13 is an enlarged cross-sectional view of the forward section ofthe flashlight of FIG. 11 taken through the plane indicated by 302-302.

FIG. 14 is an enlarged cross-sectional view of the rearward section ofthe flashlight of FIG. 11 taken through the plane indicated by 302-302.

FIG. 15A is an exploded perspective view of the head assembly and aportion of the barrel of the flashlight of FIG. 11. FIG. 15B is anexploded perspective view of the switch and tail cap assembly portion ofthe flashlight of FIG. 11.

FIG. 16A is a perspective view of a battery cassette.

FIG. 16B is an exploded perspective view of the battery cassette of FIG.16A.

FIG. 17 is a schematic diagram illustrating the internal and externalelectrical connections of the battery cassette of FIG. 16.

FIG. 18 is a circuit diagram illustrating the relationship between theelectronic circuitry according to another embodiment of the invention.

FIGS. 19A-D are schematic circuit diagrams of different components ofthe circuit shown in FIG. 18.

FIG. 20 is a cross-sectional view of a lamp module of the flashlight ofFIG. 1 taken at 90° from the cross-section included in FIG. 3.

FIG. 20A is a side view of a retaining collar, and FIG. 20B is alongitudinal cross-sectional view through the retaining collar.

FIG. 21 is a plan view of an exemplary flashlight.

FIG. 22 is a cross-sectional view of the flashlight of FIG. 21 takenalong the plane indicated by 102-102.

FIG. 23 is an enlarged cross-sectional view of the forward section ofthe flashlight of FIG. 21 taken through the plane indicated by 102-102.

FIG. 24 is an enlarged cross-sectional view of the rearward section ofthe flashlight of FIG. 21 taken through the plane indicated by 102-102.

FIG. 25A is an exploded perspective view of the head assembly and aportion of the barrel of the flashlight of FIG. 21.

FIG. 25B is an exploded perspective view of the switch and tail capassembly portion of the flashlight of FIG. 21.

FIG. 25C is a perspective view of a rechargeable battery pack.

FIG. 26 is a plan view of another exemplary flashlight.

FIG. 27 is a cross-sectional view of the flashlight of FIG. 26 takenalong the plane indicated by 302-302.

FIG. 28 is an enlarged cross-sectional view of the forward section ofthe flashlight of FIG. 26 taken through the plane indicated by 302-302.

FIG. 29 is an enlarged cross-sectional view of the rearward section ofthe flashlight of FIG. 26 taken through the plane indicated by 302-302.

FIG. 30A is an exploded perspective view of the head assembly and aportion of the barrel of the flashlight of FIG. 26.

FIG. 30B is an exploded perspective view of the switch and tail capassembly portion of the flashlight of FIG. 26.

FIG. 30C is a perspective view of a battery cassette.

FIG. 31A is a side view of a tail cap assembly.

FIG. 31B is a rear view of a tail cap assembly showing icons.

FIG. 31C is a rear view of an alternate tail cap assembly showing icons.

FIG. 31D is a tail cap assembly showing a bump on a switch.

FIG. 32 is a circuit diagram illustrating the relationship between theelectronic circuitry according to another embodiment of the invention.

FIGS. 33A-D are schematic circuit diagrams of different components ofthe circuit shown in FIG. 32.

FIGS. 34, 35, 36A, 36B and 37 are flow diagrams illustrating operationsof a flashlight according to different aspects of the invention.

DETAILED DESCRIPTION

Embodiments will now be described with reference to the drawings. Tofacilitate the description, any reference numeral representing anelement in one figure will represent the same element in any otherfigure. Further, in the following description, references to the front,forward or forward facing side of a component shall generally mean theside of the component that faces toward the front end of the flashlightor other portable lighting device. Similarly, references to the aft,back, rear or rearward facing side of a component shall generally meanthe side of the component facing the rear of the portable lightingdevice, e.g., the direction in which the tail cap is located in the caseof a flashlight.

Exemplary flashlights 100, 300 are described in connection with FIGS.1-10I and 11-19D. Each of the exemplary flashlights 100, 300 incorporatea number of distinct aspects. While these distinct aspects have all beenincorporated into flashlights 100, 300 in various combinations, thescope of the present invention is not restricted to flashlights 100, 300described herein. Rather, the present invention is directed to each ofthe inventive features of flashlights 100, 300 described below bothindividually as well as in various combinations. Further, as will becomeapparent to those skilled in the art after reviewing the presentdisclosure, one or more aspects of the present invention may also beincorporated into other portable lighting devices, including, forexample, head lamps and lanterns.

FIG. 1 shows an exemplary flashlight 100. The exemplary flashlight 100generally includes barrel 124, head assembly 104 located at the forwardend of barrel 124, and switch and tail cap assembly 106 located at therear end of barrel 124. The head assembly 104 is disposed about theforward end of the barrel 124, and the switch and tail cap assembly 106encloses the aft end of barrel 124.

FIG. 2 is a partial cross-sectional view of flashlight 100 of FIG. 1taken along the plane indicated by 102-102. FIG. 3 is an enlargedpartial cross-sectional view of the forward section of flashlight 100 ofFIG. 1 taken through the plane indicated by 102-102. (The portions ofFIGS. 2-4 that relate to the battery pack 130 are not shown incross-section.)

Referring to FIGS. 2 and 3, a light source 101 is mounted to the forwardend of the barrel 124. In the present embodiment, the light source 101is mounted so that it is disposed at the aft end of reflector 118. Inother embodiments, the reflector 118 may be omitted, or its shapechanged.

Barrel 124 is a hollow, tubular structure suitable for housing aportable source of power, such as, for example, rechargeable batterypack 130. Thus, barrel 124 serves as a housing for receiving a portablesource of power having a positive and a negative electrode.

In the illustrated embodiment, barrel 124 is sized to accommodate abattery pack 130, which contains a single Li-Ion battery cell. In otherembodiments, however, one or more alkaline dry cell or other types ofrechargeable batteries of various sizes may be used instead of therechargeable battery pack 130. To this end, barrel 124 may be sized toaccommodate the desired size battery pack or other power source.Further, if a plurality of batteries are employed, depending on theimplementation, they may be connected electrically in parallel orseries. Further, other suitable portable power sources, including, forexample, high capacity storage capacitors may also be used.

In the illustrated embodiment, barrel 124 includes a forward portion 125that extends beneath combined head and face cap 112 so that the outersurface of the head assembly 104 is generally flush with that of thebarrel 124. The inner diameter of the forward portion 125 is smallerthan the inner diameter of the rest of barrel 124. Also, the outerdiameter of the forward portion 125 may be smaller than the outerdiameter of the rest of barrel 124, so that when flashlight 100 isassembled, the outer portion of combined head and face cap 112 and theouter portion of barrel 124 may form a substantially uniform,cylindrical surface. Alternatively, the combined head and face cap 112and barrel 124 may have different shapes.

Barrel 124 is preferably made out of aluminum but other suitablematerials may be used. In certain embodiments where the barrel formspart of the conductive path of the flashlight, it is preferred thatbarrel 124 and other components comprise a conductive material, orinclude a conductive path. In other embodiments, such as that describedin conjunction with flashlight 100 below, barrel 124 need not form partof the main power circuit. In this embodiment, barrel 124 may be madeout of metal or non-metal (e.g., plastic) materials.

In the illustrated embodiment, barrel 124 includes external threads 174on the outer diameter of its forward portion 125, and internal threads131 on the inside diameter of its aft end (best seen in FIG. 4). Thebarrel 124 of the present embodiment also includes an annular shoulder182 formed at the aft end of the forward portion 125. Annular shoulder182 acts as a stop to shoulder ring 126 disposed in the forward end ofthe barrel 124.

Barrel 124 may include a textured surface 108 or surfaces along aportion of its length. The textured surface may aid the user to gripbarrel 124. In the present embodiment, textured surface 108 may beprovided by broaching, or alternatively, may be formed from machinedknurling or other process. Any desired pattern may be used for texturedsurface 108.

FIG. 5A is an exploded perspective view of head assembly 104, barrel 124and other components of flashlight 100 of FIG. 1.

Referring to FIGS. 3 and 5A, head assembly 104 of the present embodimentincludes combined head and face cap 112, lens 116, and reflector 118.

The internal surface of combined head and face cap 112 may be used tohouse certain components, including, for example, lens 116 and reflector118. The reflector 118 and lens 116 are operatively mounted to the innerdiameter of the combined head and face cap 112. In the presentembodiment, reflector 118 includes spring clips 177 extending from itsfront end so that reflector 118 may snap into a corresponding annularrecess 117 formed near the forward end of the inner portion of combinedhead and face cap 112. An annular shoulder 119 is provided at the aftend of annular recess 117 to attach reflector 118 to the combined headand face cap 112 once spring clips 177 expand into annular recess 117.Lens 116 is interposed between a forward facing flange of reflector 118and an inwardly turned lip of the combined head and face cap 112. Inthis manner, reflector 118 and lens 116 are locked within the combinedhead and face cap 112.

Reflector 118 may include fins 176 distributed around the outerperimeter of reflector 118 to provide structural integrity to reflector118 and to help properly align reflector 118 within the internal surfaceof the forward portion 125 of barrel 124.

Combined head and face cap 112 may include internal threads 172 whichare configured to engage with external threads 174 on the forward end ofbarrel 124. In other implementations, however, other forms of attachmentmay be adopted. Combined head and face cap 112 is preferably made fromanodized aluminum, though other suitable materials may be used.

A sealing element, such as an o-ring 114, may be located at theinterface between combined head and face cap 112 and lens 116 to providea watertight seal. Other water resistant means, such as a one-way valve,may also be used. O-ring 114 may comprise rubber or other suitablematerial.

As best seen in FIGS. 3 and 5A, the reflective profile 121 of thereflector 118 is preferably a segment of a computer-generated optimizedparabola that is metallized to ensure high precision optics. In oneembodiment, the profile 121 may be defined by a parabola having a focallength of less than 0.080 inches, and more preferably between0.020-0.050 inches. Further, the distance between the vertex of theparabola defining the profile 121 and the aft opening of the reflector121 may be 0.080-0.130 inches, and more preferably 0.105-0.115 inches.The opening of the forward end of the reflector 118 may have a diameterof 0.7-0.8 inches, and more preferably 0.741-0.743 inches, and theopening of the aft end of the reflector 118 may have a diameter of0.2-0.3 inches, and more preferably 0.240 to 0.250 inches. Further, theratio between the distance from the vertex to the opening of the aft endof the reflector 118 and the focal length may be in the range of 1.5:1and 6.5:1, and more preferably 3.0:1 to 3.4:1. Moreover, the ratiobetween the distance from the vertex to the opening of the forward endof the reflector 118 and the focal length may be in the range of 20:1and 40:1, and more preferably 26:1 to 31:1. It should be noted thatthese are examples only, and other values are provided later.

Reflector 118 preferably comprises an injection molded plastic, thoughother suitable materials may be used.

Referring back to FIG. 3, although the embodiment disclosed hereinillustrates a substantially planar lens 116, the flashlight 100 mayinstead include a lens that has curved surfaces to further improve theoptical performance of the flashlight 100. For example, the lens mayinclude a biconvex profile or a plano-convex profile in the whole orpart of the lens surface.

Referring to FIGS. 3 and 5A, an o-ring 122 may be located in an annulargroove 123 provided in the outer surface of the barrel 124 at theinterface between combined head and face cap 112 and forward portion 125of barrel 124 to provide a watertight seal. Other water resistant meanssuch as a one-way valve or lip seal may also be used.

Flashlight 100 of the present embodiment includes a lamp module 128mounted within the shoulder ring 126 at the forward end of barrel 124 sothat light source 101 is disposed at the aft and of reflector 118. Lampmodule 128 may have a principal axis 110 of projection which maycoincide with the reflector axis and/or the longitudinal axis offlashlight 100. In view of the foregoing arrangement, the focus of lightemitted from lamp module 128 may be adjusted by twisting head assembly104 relative to barrel 124, which may be provided by mating threads 172,174. The light source 101 of lamp module 128 includes a first, positiveelectrode in electrical communication with a compressible positivecontact 133 (see FIGS. 3 and 20) via second circuit board 135 and asecond, negative electrode in electrical communication with the heatsink housing 188, which also acts as the negative contact of lamp module128.

The light source 101 may be any suitable device that generates light.For example, the light source 101 can be an LED lamp, an incandescentlamp, or an arc lamp. In the illustrated embodiment, the light source101 is an LED lamp and lamp module 128 is an LED module. LED 137 (FIG.20) of lamp module 128 preferably substantially radiates light at aspherical angle of less than 180°. In other embodiments, LEDs with otherangles of radiation may be used, including LEDs that radiate at an anglegreater than 180°.

The structure of an LED module that may be used for lamp module 128 isdescribed in detail in co-pending U.S. patent application Ser. No.12/188,201, by Anthony Maglica, the contents of which are herebyincorporated by reference.

FIG. 20 is a cross-sectional view of the lamp or LED module 128 inisolation. The cross-sectional view shown in FIG. 20 is taken at 90° tothe cross-sectional view shown in FIG. 3. The lamp module 128 of thepresent embodiment includes an LED 137 as light source 101, a firstcircuit board 139, a lower assembly 141 formed by compressible positivecontact 133 and a lower insulator 129, the second circuit board 135, anupper assembly 143 formed by an upper insulator 145 and an upperpositive contact 147 and an upper negative contact 155 (see FIG. 3), anda heat sink 149 formed by the outer heat sink housing 188 and a contactring 151, which are preferably made out of metal.

Referring to FIGS. 3 and 20, for redundancy, the compressible positivecontact 133 preferably includes two clips 153 for making electricalcontact with second circuit board 135, one of the clips 153 beingdisplaced before the page in the cross-sectional view provided in FIG.20. The second circuit board 135 is in electrical contact with upperpositive contact 147 and an upper negative or ground contact 155 (seeFIG. 3), which are preferably solder connected to the bottom side of thefirst circuit board 139. For redundancy, the upper positive contact 147preferably includes two clips 157, one of which is displaced before thepage in the view provided in FIG. 20. The upper ground contact alsoincludes two clips 157 for making electrical contact with the secondcircuit board 135, one of which is displaced behind the clip 157 of theupper positive contact shown in FIG. 20 and one of which is displacedbefore the page in the view provided in FIG. 20. The upper positivecontact 147 is in electrical communication with the positive electrodeof LED 137 via first circuit board 139 and the upper ground contact isin electrical communication with the heat sink 149 via the first circuitboard 139.

The LED 137 and the heat sink 149 are affixed to the first circuit board139, preferably via a solder connection. The first circuit board 139,which preferably is a metal clad circuit board having a plurality ofthermally conductive layers connected by thermal vias, promotes therapid and efficient transfer of heat from the LED 137 to the heat sink149.

The LED 137 can be any light emitting diode that can be soldered to aprinted circuit board. Preferably the LED 137 can be soldered to thefirst circuit board 139 using a screen applied solder paste and a reflowoven. More preferably, the LED 137 is the LUXEON* Rebel productcommercially available from Philips Lumileds Lighting Company, LLC.

The second circuit board 135 includes the circuitry for driving LED 137.In the present embodiment, the second circuit board 135 includes alinear buck regulating circuit to reduce driving voltage to the lampmodule 128, because the voltage delivered by assembled circuit board 240is much higher than the operating voltage of LED 137. In otherimplementations, however, the second circuit board 135 may include alinear boost regulating circuit for providing an adequate voltage to LED137 when the driving voltage to the lamp module 128 is lower than theoperating voltage of one or more LEDs 137 that are to be driven. Inother words, the second circuit board 135 may provide a buck or a boostoperation depending on the needs of the load and the battery voltage. Ifthe battery voltage is high, the buck operation would be performed. Onthe other hand, if the battery voltage is low, the boost operation wouldbe performed. In some implementations, a buck operation may be performedinitially, while a boost operation is provided after the voltage of thebatteries had dropped below a certain level.

The lower assembly 141 is preferably formed by co-molding compressiblepositive contact 133 and a lower insulator 129 together. Likewise, upperassembly 143 is preferably formed by co-molding upper insulator 145 andan upper positive contact 147 and an upper negative contact 155together. Thus, the upper and lower insulator are preferably formed froman injection moldable plastic with suitable structural and thermalqualities for the application.

The upper positive and negative contacts of the upper assembly 143 aresoldered to the bottom of the first circuit board 139, the front side ofwhich is in turn soldered to contact ring 151, which can be press fitand/or soldered to heat sink housing 188. Thus, the upper assembly 143is firmly held within heat sink housing 188 in the present embodiment.Further, the circumference of heat sink housing 188 is crimped into anannular recess 161 of the lower insulator 129. The crimping of heat sinkhousing 188 into annular recess 161 holds lower insulator 129 and hencethe lower assembly 141 within heat sink housing 188.

When flashlight 100 is in the ON state, the heat sink housing 188thermally and electrically couples the light source 101 and the shoulderring 126. In addition, the heat sink housing 188 electrically couplesthe ground path of the second circuit board 135 to the shoulder ring126. The heat sink housing 188 therefore acts as the negative, orground, contact for the lamp module 128. Further, by arranging the heatsink housing 188 as shown in FIG. 3 so that it is in good thermalcontact with the shoulder ring 126, which in turn, as more fullyexplained below, is in good thermal contact with barrel 124, when theflashlight 101 is ON, heat that is generated by the light source 101 isefficiently absorbed and/or dissipated by the first circuit board 139 tocontact ring 151, the heat sink housing 188, shoulder ring 126, andfinally barrel 124. Thus flashlight 101 is able to effectively protectthe light source 101 from being damaged due to heat. Preferably, theheat sink housing 188 is made from a good electrical and thermalconductor, such as aluminum.

The heat sink housing 188 is formed so that it flares in a region 169toward the back or bottom of the lamp module 128 from a first region 163having a first diameter to a second region 167 having a second, largerdiameter. The diameter of the first region 163 is sized so that it canclosely fit within an annular lip 186 of shoulder ring 126 while at thesame time, making thermal contact therewith. An aft facing surface ofthe annular lip 186 forms a contact surface 187. The outer diameter ofthe lower insulator 129 and heat sink housing 188 are sized so thatthere is little or no play in the radial direction between the innerwall of the shoulder ring 126 and the lower insulator 129 and heat sinkhousing 188. In this way, when lamp module 128 is pushed far enoughforward within shoulder ring 126 so that the flared region 169 of theheat sink housing 188 comes into contact with the contact surface 187 ofthe annular lip 186, the heat sink housing 188 will be in thermal andelectrical contact with shoulder ring 126 in the first, second andflared regions 163, 167, 169, respectively.

The outer surface of the heat sink housing 188 also includes an annularrecess 171 in the region 163 of the first diameter. The annular recess171 is generally perpendicular to the axis of the heat sink and thebarrel 124. In addition, the annular recess 171 is positioned to receivelocking tabs 173 (see FIG. 20A) of retaining collar 120 when the lampmodule 128 is mounted within the forward end of barrel 124 in shoulderring 126.

The flared region 169 of the heat sink housing 188 is preferably shapedto mate with contact surface 187 along as much surface area as possibleto facilitate electrical and thermal communication between the lampmodule 128 and the shoulder ring 126. The flared region 169 of the heatsink housing 188 is also sized so that once disposed in the shoulderring 126, the axial movement of the heat sink housing 188, and,consequently, the lamp module 128, in the forward direction will belimited by the annular lip 186 of the shoulder ring 126.

The lower insulator 129 includes at its back face 175 a recess 178,which is surrounded by an annular shoulder 179 so that the recess iscentrally located. The recess 178 is dimensioned to be deeper than theheight of the positive top contact 214 b of battery pack 130. However,as shown in FIGS. 2 and 3, when the battery pack 130 is urged forwardagainst the back face 175 of the lower insulator 129, the positive topcontact 214 b of battery pack 130 engages with the compressible positivecontact 133. In this way, the lamp module 128 provides a simpleconfiguration that enhances the electrical coupling between componentseven when the flashlight is jarred or dropped, which may cause thebattery pack 130 to suddenly displace axially within the barrel 124.Further, because the compressible positive contact 133 may absorb impactstresses due to, for example, mishandling, and recess 178 is deeper thanthe positive top contact 214 b of battery pack 130, the battery pack 130and its electronics, which are discussed below, are well protected fromphysical damage during use of the flashlight 100.

Also, because compressible positive contact 133 is disposed forward ofthe shoulder 179 of back face 175, if a battery pack 130 is insertedbackwards into the barrel 124, no electrical coupling with compressiblepositive contact 133 is formed. Accordingly, the configuration of thelamp module 128 and its arrangement within barrel 124 will help toprotect the flashlight's electronics from being affected or damaged byreverse current flow.

The retaining collar 120 attaches to the heat sink housing 188 of thelamp module 128 and, among other things, limits axial movement of thelamp module 128 in the rearward direction when battery pack 130 isremoved from flashlight 100. The retaining collar 120 attaches to thelamp module 128 at the annular recess 171 of the heat sink housing 188.

Referring to FIGS. 3, 20A and 20B, the retaining collar 120 includescircumferential locking tabs 173, which project inwardly from the innersurface of the retaining collar 120, and ribs 181, which projectoutwardly from the outer surface of the retaining collar 120. Referringto FIG. 3, each of the locking tabs 181 is sized to fit into the annularrecess 171 on the exterior of the heat sink housing 188. A plurality ofribs 181 are preferable spaced equally around the exterior circumferenceof the retaining collar 120 so as to generally extend in the axialdirection of the retaining collar 120. The ribs 181 preferably extendfrom the front of the retaining collar to slightly over half the axiallength of retaining collar 120. The ribs 181 are dimensioned so as tolimit the amount of radial play between the forward end of the lampmodule 128 and the inner diameter of the shoulder ring 126 to adesirable amount. The ribs 181 are also preferably dimensioned toproject outwardly from retaining collar 120 by the same or a greaterdistance than the locking tabs 173 project inwardly. By only having theribs extend to about the middle of the retaining collar 120, the aft end183 of the retaining collar 120 can expand sufficiently over the outersurface of the heat sink housing 188 within the shoulder ring 126 untilcircumferential locking tabs 173 snap into annular recess 171 (see FIG.3). Once the circumferential locking tabs 173 are snapped into annularrecess 171, the rearward movement of the lamp module 128 is confined bythe annular lip 186. Thus, by securing the retaining collar 120 to thelamp module 128, which is disposed in the shoulder ring 126, theretaining collar 120 keeps the lamp module 128 from falling to the rearof barrel 124, and potentially out the back end of the flashlight 100,in the absence of battery pack 130 being installed in the flashlight100. In a preferred embodiment, the retaining collar 120 is made from aninsulator such as, for example, plastic.

Referring to FIG. 3, the shoulder ring 126 forms a large heat sink.Moreover, because it has a mass that is substantially greater than thatof lamp module 128, it quickly draws heat away from heat sink 149 oflamp module 128. Ultimately, the heat drawn away by shoulder ring 126 isefficiently drawn into barrel 124 because barrel 124 and shoulder ring126 are preferably in intimate metal to metal contact in the forwardregion 189 of reduced diameter of shoulder ring 126. Shoulder ring 126may be made out of metal, and more preferably nickel plated aluminum forenhanced thermal, electrical and corrosion resistance properties.

Shoulder ring 126 includes shoulder 180 formed at the interface of theforward region 189 of reduced diameter and an aft region 191 ofincreased diameter. The forward region 189 includes a plurality ofsplines 193, as best seen in FIG. 5A. Splines 193 are preferably spacedequally around the circumference of a portion of the forward region 189of shoulder ring 126 so as to generally extend in the axial direction ofthe shoulder ring 126. The outer diameter of the forward region 189 ofshoulder ring 126 is dimensioned so that it will provide an interferencefit with the inner wall of the forward portion 125 of barrel 124 and sothat splines 193 will cut into the inner wall of the forward portion 125of barrel 124 when shoulder ring 126 is press fitted into the forwardportion 125 of the barrel 124.

When shoulder ring 126 is press fitted into the forward portion 125 ofbarrel 124, the splines 193 will splay and cut into metal on the innerdiameter of the forward portion 125 of barrel 124. Annular reliefgrooves are provided adjacent the forward and aft ends of splines 193 onshoulder 126 to receive metal from barrel 124 that is displaced duringthe press fitting operation. In this way, shoulder ring 126 ispermanently locked in metal to metal contact with the forward portion125 of barrel 124.

The diameter of the aft region 191 of shoulder ring 126 is slightlysmaller than the inner diameter of the aft portion of barrel 124 so thatit can readily slide within barrel 124 without damaging any protectivecoating, such as that resulting from an anodizing treatment process.

The above arrangement is also desirable because the splines 193 will cutthrough any anodized coating provided on the interior of barrel 124,thereby providing the possibility of using the barrel as a ground pathas described, for example, in connection with flashlight 300 describedbelow without having to make a skin cut to remove anodizing or mask thecontacting area before an anodizing treatment as has been conventionallyrequired with aluminum flashlights.

While shoulder ring 126, lamp module 128, and head assembly 104 do notform part of a mechanical switch for flashlight 100 in the presentembodiment, in other embodiments they could as described, for example,in U.S. patent application Ser. No. 12/353,396, filed Jan. 14, 2009, byStacey West, the contents of which are hereby incorporated by reference.

Lamp module 128 is electrically coupled to flashlight 100 as follows.Flashlight 100 may include rechargeable battery pack 130 that includespositive top contact 214 b which is electrically coupled to compressiblepositive contact 133 of lamp module 128. After the current passesthrough the light source, a ground connection extends from the negativeelectrode of the light source through heat sink housing 188, which actsas the negative contact of lamp module 128 and shoulder ring 126, whichin turn is electrically coupled to outer ring top contact 212 whichfunctions as the negative electrode of battery pack 130.

FIG. 4 is an enlarged partial cross-sectional view of the rearwardsection of flashlight 100 of FIG. 1 taken through the plane indicated by102-102. (In FIG. 4, however, battery pack 130 is not shown incross-section.) The rearward section of flashlight 100 generallycomprises switch and tail cap assembly 106. FIG. 5B is an explodedperspective view of switch and tail cap assembly 106.

Referring to FIGS. 4 and 5B, switch and tail cap assembly 106 of thepresent embodiment preferably includes snap ring 132, lower switchhousing 134, contact pins 136, 138, 140, contact pin springs 142, 144,146, 156, 158, circuit board 148, wave spring 150, snap dome 152,actuator 154, upper switch housing 160, lip seal 162, inner tail capsection 164, charging ring 166, switch port seal 168, and outer tail capsection 170.

Lower switch housing 134 preferably includes three cylindrical channels193 opened to the forward end of lower housing 134 for receiving andholding one of contact pins 136, 138, 140. Each of the channels isconnected to a cylindrical chamber 195 which is axially aligned with thechannel 193. The diameter of each cylindrical chamber 195 is larger thanthe channel diameter so that each chamber may receive and house one ofcontact pin springs 142, 144, 146 in compression between a shoulder oncontact pins 136, 138, 140 and circuit board 148 as shown. Springs 142,144, 146 serve to push contact pins 136, 138, 140 forward until theirrespective shoulders engage the end wall of its respective chamber 195.In the present embodiment, lower switch housing 134 preferably comprisesa non-conductive material, such as plastic, but other suitable materialsmay be used. Contact pins 136, 138, 140 and contact pin springs 142,144, 146 are preferably made out of metal so as to form part of theelectrical paths of flashlight 100 to be described later. In the presentembodiment, contact pins 136, 138, 140 may comprise a conductive metal,such as aluminum while contact pin springs 142, 144, 146 may comprise asuitable conductive spring metal, such as music wire.

The channels 193 of lower switch housing 134 are configured to alignwith contacts on the bottom of battery pack 130. When battery pack 130is installed, contact pin 136 may be aligned with a bottom centralcontact 274 b (FIG. 6) of battery pack 130, contact pin 138 may bealigned with a bottom middle ring contact 276 (FIG. 6) of battery pack130, and contact pin 140 may be aligned with a bottom outer ring contact278 (FIG. 6) of battery pack 130. In this configuration, as best seen inFIG. 5B, contact pin 136 is electrically coupled to GND connection onthe printed circuit board 240 in the battery pack 130 to be describedbelow. Similarly, as shown in FIG. 5B, contact pin 138 is electricallycoupled to a MOM contact, and contact pin 140 is electrically coupled to+5 VDC contact of printed circuit board 240 of battery pack 130.

Circuit board 148 preferably includes contacts on both of its sides.Circuit board 148 may also include conductive vias routed through board148 to couple contacts on opposite sides. The front side of circuitboard 148 (which is facing lower switch housing 134) includes threecontact pads (labeled GND, MOM, and +5 VDC in FIG. 7) that areelectrically coupled to contact pin springs 142, 144, 146, respectively.The rear side of circuit board 148 (which is facing the upper switchhousing 160) includes three corresponding contact pads that correspondto GND, MOM and +5 VDC and that are located at designated locations.Each pair of the corresponding contacts on the front side and rear sideof circuit board 148 are electrically connected through conductive viasprovided in circuit board 148, or alternatively routing wires.

Upper switch housing 160 includes a cylindrical channel 197 that allowsactuator 154 to slide within. An annular rim of switch port seal 168 isheld between an annular lip 199 of outer tail cap 170, which is locatedat the rear end of flashlight 100, and charging ring 166. When a userpresses on switch port seal 168, actuator 154 is moved forward withinchannel 197 and engages snap dome 152 such that the MOM and GND contactpads on the rear side of circuit board 148 are electrically coupledthrough snap dome 152. When the user releases switch port seal 168, theMOM and GND contact pads on the rear side of circuit board 148 are nolonger electrically coupled through snap dome 152.

In the present embodiment, upper switch housing 160 and actuator 154preferably comprise a non-conductive material such as plastic. Switchport seal 168 preferably comprises a flexible non-conductive material,such as rubber. Snap dome 152 preferably comprises a conductive springmetal. Other suitable material may be used.

Charging ring 166 is configured to include an exposed charging contact190, made out of metal, and preferably nickel plated, for contacting thepositive contact of an external charging unit such as a charging cradle.The metal charging contact 190 may be electrically connected to two ears196 radially extending into slots 198 of the inner tail cap section 164.Ears 196 preferably comprise metal so as to form part of the conductivepath of the recharging circuit.

Two insulating rings 194, preferably comprising a non-conductivematerial or a non-conductive coating over a conductive material, may belocated on either side of metal charging contact 190 to prevent theconductive portions of charging ring 166, namely metal charging contact190 and ears 196, from electrically contacting inner tail cap section164 or outer tail cap 170. In the present embodiment, insulating rings194 are molded plastic, preferably co-molded with the charging contact190.

Ears 196 electrically contact the rear end of coil springs 156, 158 thatare retained within channels formed in upper switching housing 160. Theforward end of coil springs 156, 158 are electrically connected to the+5 VDC contact pad on the rear side of circuit board 148. As previouslydescribed, the +5 VDC contact on the rear side of circuit board 148 isfurther connected to the +5 VDC contact pad on the front side of circuitboard 148. The +5 VDC contact pad on the front side of circuit board 148is in contact with contact pin spring 146 retained in lower switchhousing 134. Therefore, charging contact 190 is electrically coupled tothe +5 VDC outer ring contact 212 on the bottom of battery pack 130through ears 196 of charging ring 166, springs 156, circuit board 148,contact pin spring 146 and contact pin 140.

In the present embodiment, the negative contact of the charging circuitis provided by charging contact 192 on inner tail cap section 164. Theinner tail cap section 164, including the charging contact 192, ispreferably nickel plated. Although provided on inner tail cap section164, as seen in FIG. 4, charging contact 192 forms a part of theexternal surface of flashlight 100. Inner tail cap section 164 iselectrically coupled to the GND contact pad on the rear side of circuitboard 148 through wave spring 150. Therefore, negative charging contact192 is electrically coupled to the GND central contact 274 b on thebottom of battery pack 130 through inner tail cap section 164, wavespring 150, circuit board 148, contact spring 142 and contact pin 136.

As best seen from FIGS. 4 and 5B, charging contacts 190, 192 serve asthe interface between an external recharging unit and rechargeablebattery pack 130 of flashlight 100. Although not depicted here, thoseskilled in the art will appreciate that the cradle of the rechargingunit should be fashioned in a way to make electrical contact withexternal charging contacts 190, 192 and hold flashlight 100 in placewhile charging takes place. Because charging contacts 190, 192preferably extend around the entire external circumference of flashlight100, a recharging unit having a simple cradle design may be used. Forexample, a cradle design that permits flashlight 100 to be placed intothe recharging unit in any radial orientation relative to itslongitudinal axis and still be able to make contact with the rechargingunit's charging contacts may be used. Thus, flashlight 100 does not needto be pressed into the charging unit so that hidden plugs or tabs areinserted into flashlight 100 in order to make contact with the chargingcontacts of the recharging unit.

Charging contacts 190, 192 of the present embodiment are preferably inthe form of charging rings to simplify the recharging procedure, i.e.,to allow placing flashlight 100 in a cradle at any radial orientation.However, other forms of charging contacts may also be used.

In the present embodiment snap ring 132 may be placed between the frontedge of lower switch housing 134 and inner tail cap section 164 toprevent lower switch housing 134 from moving forward.

Wave spring 150 may be provided between the rear edge of circuit board148 and an annular lip of inner tail cap section 164 to provide acompressible spring contact between the two. Wave spring 150 alsoapplies a biasing force to circuit board 148, which in turn applies thebiasing force to lower switch housing 134, thereby serving to presscover switch housing 134 against snap ring 132.

Inner tail cap section 164 preferably includes threads 165 on the frontouter surface of inner tail cap section 164 for mating with threads 131on the rear inner surface of barrel 124.

The outer diameter of the aft end 201 of inner tail cap section 164 andthe inner diameter of the outer tail cap section 170 are preferablysized so that outer tail cap 170 may be permanently press fitted ontothe aft end 201 of inner tail cap section 164 thereby forming anintegral switch and tail cap assembly 106.

Inner tail cap section 164 preferably comprises a conductive materialsuch as aluminum.

A one-way valve, such as a lip seal 162, may be provided at theinterface between barrel 124 and switch and tail cap assembly 106 toprovide a watertight seal while simultaneously allowing overpressurewithin flashlight 100 to vent to the atmosphere. However, other forms ofsealing elements, such as an o-ring, may be used instead of one-wayvalve 162 to form a watertight seal. Lip seal 162 preferably comprises anon-conductive material such as rubber.

Other configurations of switch and tail cap assembly 106 may be used.For example, the switch function may be included in a side, push buttonswitch or in an internal rotating head assembly switch such as thatemployed in U.S. patent application Ser. No. 12/353,396, filed Jan. 14,2009.

Referring now to FIGS. 5A, 6 and 7, the rechargeable battery pack 130 isnow further described. In general, battery pack 130 preferably includesa rechargeable battery, a circuit board containing electronics such asrecharging circuit and/or circuits for other functions and contacts toelectrically connect battery pack 130 to the rest of the flashlight 100or other lighting device. As such, battery pack 130 may generallyrepresent a self-contained unit that may be inserted into batterycompartment 127 of barrel 124 along with the other components shown inFIG. 5A. It is also preferred that battery pack 130 provides protectionfor the electronics and other components therein.

As shown in FIG. 6, battery pack 130 includes front or lamp end capassembly 210, battery housing 230, assembled circuit board 240, battery260 and rear or tail cap assembly 270. These components are discussed inturn below.

In the present embodiment, front or lamp end cap assembly 210 includesfront end cap 211, outer ring top contact 212, universal positive topcontact 214, positive top contact 216 and battery pack spring 218. Eachcontact 212, 214, 216 preferably includes a circuit board clip as shownby clips 212 a, 214 a, 216 a. When assembled, outer ring top contact 212is located on the outside or forward side of front end cap 211, whilecontacts 214, 216 and battery pack spring 218 are located on the insideor rear side of front end cap 211.

Front end cap assembly 210 is preferably manufactured in a manner thatreduces the number of steps needed to assemble its components. To thisend, front end cap 211 may be formed by injection molding from a plasticor other suitable material. This injection molding process preferablyincludes the co-molding of one or more of contacts 212, 214, 216 alongwith end cap 211. That is contacts 212, 214, 216 may be positioned inthe injection molding machine so that they become encompassed orotherwise held in place relative to each other by the injected materialas it solidifies. Thus, the contacts are preferably located in theinjection molding machine so that they end up in the appropriatepositions to form end cap assembly 210 and the relevant parts of theelectrical path as described later. Contacts 212, 214 215 may alsoinclude circuit board clips similar to that of the contacts included inthe front end cap 211. Though the foregoing co-molding process ispreferred, front end cap 211 and contacts 212, 214, 216 may be assembledby other suitable means. Thereafter, spring 216 may be press fittedbetween a plurality of retaining walls provided on the rear side offront end cap 211, like the retaining walls 271 shown in FIG. 6 on rearend cap 279.

After front end cap assembly 210 is assembled, it may be press fit intothe front or lamp end of housing 230. Preferably end cap 211 and housing230 are provided with mutually cooperating features to lock end cap 211to housing 230. Such features may include for example opposing tabs 290and holes 291. Other embodiments may employ other suitable means.

Rear or tail end cap assembly 270 of the present embodiment includesbattery pack spring 272, bottom negative contact 274, inner ring contact276, outer bottom ring contact 278 and rear end cap 279. Each contact274, 276, 278 may include a circuit board clip as shown by clips 274 a,276 a, 278 a. When assembled, battery pack spring 272 and bottomnegative contact 274 may be located on the forward or inner side of endcap 279, while inner ring contact 276 and outer bottom ring contact 278may be located on the rear or outer side of end cap 279.

Rear end cap 279 and one or more of contacts 274, 276, 278 may beco-molded as described above, so that the contacts are appropriatelylocated relative to each other to form end cap assembly 270 and therelevant parts of the electrical path described later. Alternatively,contacts 274, 276, 278 may be assembled by other suitable means.Thereafter, spring 272 may be press fitted between a plurality ofretaining walls 271 provided on the forward side of rear end cap 279.

When rear end cap assembly 270 is assembled, it may be press fit intothe rear or tail cap end of housing 230. Preferably rear end cap 279 andhousing 230 are provided with mutually cooperating features to lock rearend clip 279 to housing 230 such as opposing tabs 290 and holes 291.This may occur through tabs, on rear end housing 270 that correspond toholes in housing 230, or by other suitable means.

Front end cap 211 and rear end cap 279 may also include electricalcontact guides that are located on the inner side of each end cap 211,279. FIG. 6 shows guides 281, 282, 283 on the inner side of rear end cap279. Though not shown in FIG. 6, front end cap 211 may include guides281, 282, 283 on its inner surface. As discussed later, these guidesprovide structural support to and help position circuit board clips 212a, 214 a, 216 a, 274 a, 276 a, and 278 a of the electrical contacts 212,214, 216, 274, 276, 278 so that the clips properly engage assembledcircuit board 240. Guides 281, 282, 283 may be formed contiguously withend caps 211, 279 during the injection molding process, or may beattached to the end cap by other suitable means.

Battery housing 230 preferably has an outer diameter to fit within theinner diameter of flashlight barrel 124. Though battery housing 230 andbattery pack 130 depicted in the figures are cylindrical to accommodateflashlight barrel 124, battery pack 130 may be configured in othershapes to accommodate different types of lighting device housings, e.g.,square or rectangular lanterns.

As shown in FIG. 6, housing 230 preferably includes a wall 231 ofsuitable thickness that extends around its circumference or perimeter.The thickness of wall 231 is preferably sufficient to provide structuralintegrity to the overall battery pack 130 and thereby protect theelectronics and other contents contained therein. Similarly, housing 230is preferably constructed of a plastic or other sufficiently strongmaterial that provides such protection.

Wall 231 preferably includes recess 232 which may extend axially alongthe length of housing 230. Recess 232 may include grooves or notches 233that may also extend axially along the length of housing 230. Recess 232and notches 233 are preferably configured to receive assembled circuitboard 240, such as by a slip fit.

Because assembled circuit board 240 is contained within housing 230,battery 260 is located off-center in the present embodiment to conservespace. This may be seen in FIG. 6 by the variation in the thickness ofwall 231 of housing 230. As shown, the thickness of wall 231 increasesnear the location where assembled circuit board 240 is located. Theadditional thickness allows recess 232 and notches 233 to be formed inwall 231. This additional thickness also permits the inner surface ofwall 231 to be cylindrical to correspond with the outer surface ofbattery 260 and provide for a snug fit. And as shown, the outer surfaceof housing 230 is also cylindrical to correspond with the inner diameterof flashlight barrel 124.

As noted above, in other embodiments, battery pack 130 may be formed innon-cylindrical configurations to accommodate non-cylindrical lightingdevices. If so, housing 230 and its wall 231 may be differentlyconfigured to accommodate a battery circuit board 24 as well as theshape of such alternate lighting devices.

The active area of assembled circuit board 240, i.e., that part ofassembled circuit board 240 which generally contains the electronics,preferably does not extend to the board edge areas 241. When assembledcircuit board 240 is fitted within housing 230, edge areas 241preferably fit within notches 233 thereby securing assembled circuitboard 240 within housing 230.

Assembled circuit board 240 includes front electrical contacts 242 a,242 b, 242 c and rear electrical contacts 244 a, 244 b, 244 c. Whenbattery pack 130 is assembled, these electrical contacts areelectrically coupled to the circuit board clips included on each contactof the front and rear end cap assemblies 210, 270 to form part of theconductive path of battery pack 130. More specifically the followingcircuit board clip/circuit pad connections are formed in battery pack230 of the present embodiment 212 a/242 a, 216 a/242 b, 214 a/242 c and276 a/244 a, 274 a/244 b and 278 a/244 c. As shown in FIG. 6, eachcircuit board clip comprises prongs that grip the assembled circuitboard 240. Guides 281, 282, 283 (and similar guides on the inner side offront end cap guides on the inner side of front end cap 211) may helpposition and support the tabs to ensure that these electricalconnections are made and that the circuit board clips are not damaged.

The electrical conductive paths of battery pack 130 are now describedwith reference to FIGS. 6 and 7. As shown, rechargeable battery 260includes positive terminal 262 and negative terminal 264.

Positive terminal 262 is coupled to assembled circuit board 240 throughbattery pack spring 218, positive top contact 216 and circuit board clip216 a that is formed as part of positive top contact 216. Circuit boardclip 216 a is preferably coupled to contact pad 242 b on assembledcircuit board 240. (It should be noted that in FIG. 7, the referencenumerals do not show the physical components but instead are used toschematically indicate the electrical connection provided thereby.)

This positive path continues on circuit board 240 to contact pad 242 cwhich is coupled to circuit board clip 214 a that is formed as part ofuniversal positive top contact 214. This path extends through contact214 to the top positive central contact 214 b; in the presentembodiment, a knub that may be formed as part of contact 214. Knub 214 bpreferably extends to the exterior of battery pack 130 and forms thepositive electrode which contacts the positive compressible contact 133of the lamp module 128. This connection is represented as dotted line215 a in FIG. 7.

The heat sink housing 188 of lamp module 128 is then grounded to batterypack 130 through shoulder ring 126 which is in turn in contact with theouter ring top contact 212 forming the negative electrode of batterypack 130. This connection is represented by dotted line 215 b in FIG. 7.Circuit board clip 212 a then is coupled to contact pad 242 a onassembled circuit board 240.

The negative terminal 264 of battery 260 may be electrically coupled toassembled circuit board 240 through battery pack spring 272, bottomnegative contact 274 and circuit board clip 274 a that is formed as partof contact 274. Circuit board clip 274 a preferably extends throughguide 282 and engages contact pad 244 b on assembled circuit board 240.

Further, knub 274 b of bottom negative contact 274 extends to theexterior of battery pack 130 and forms a negative electrode or a knub274 b for making external contact with the ground contact pad on thecircuit board 148 through contact pin 136 and pin spring 142. Thisconnection is represented by the dotted line shown as 289 b in FIG. 7.

An electrical path for the momentary switch may also extend fromassembled circuit board 240 to the switch and tail cap assembly 106 asfollows. Electrical contact pad 244 c on assembled circuit board 240 iscoupled to circuit board clip 278 a that is formed as part of outerbottom ring contact 278 and that extends through guide 283. Outer ringcontact 278 forms the external positive charging contact for batterypack 130. It is coupled to the +5 VDC contact pad on circuit board 148contained within the switch and tail cap assembly 106 through contactpad 140 and pin spring 146. This circuit path is represented by dottedline 289 a in FIG. 7.

Another electrical path extends from assembled circuit board 240 asfollows. Electrical contact pad 244 a on assembled circuit board 240 iscoupled to circuit board clip 276 a that is formed as part of inner ringcontact 276. Inner ring contact 276 may then be coupled to the MOMcircuit pad on circuit board 148 contained within the switch and tailcap assembly 106 through contact pin 138 and pin spring 144. Thiselectrical path couples the momentary switch to the assembled circuitboard 240.

The electrical circuits of flashlight 100 and the functions they serveare now further described. The electrical circuits of flashlight 100include a main power circuit to power the light source 101, a controllercircuit for powering the controller and other electronics on assembledcircuit board 240 and a charging circuit for recharging rechargeablebattery 260.

The main power circuit for the light source extends from positiveelectrode 262, through spring 218, positive top contact 216, circuitboard clip 216 a, contact pad 242 b, assembled printed circuit board240, contact pad 242 c, circuit board clip 214 a, universal positivecontact 214 to the LED or other light source through the circuit pathdescribed above represented by dotted line 215 a. The LED or other lightsource is then grounded to battery pack 130 via the negative electrodeformed by outer ring top contact 212 through the circuit path describedabove represented by dotted line 215 b. The circuit then extends throughcircuit board clip 212 a, contact pad 242 a, assembled printed circuitboard 240, contact pad 244 b, circuit board clip 274 a, bottom negativecontact 274, and spring 272 to negative terminal 264 of rechargeablebattery 260.

This circuit differs from circuits found in certain existingflashlights, in that it is generally self-contained within the batterypack. For example, certain existing flashlights use the barrel as partof the grounding connection in the circuit used to power the lightsource. However, the main power circuit of the current embodiment doesnot rely on an electrical path that includes the barrel, head, or tailcap as part of the main power circuit to power light source 101. This isadvantageous because where the barrel is used to complete the circuit, amanufacturing step is typically required to remove or machine the barrelsurface to provide a good conductive path. However, the self-containednature of the power circuit of the current invention avoids any suchstep which may reduce manufacturing costs and complexity.

The circuit to power the controller of assembled circuit board 240 mayextend from positive electrode 262, through spring 218, positive topcontact 216, circuit board clip 216 a and contact pad 242 b of assembledcircuit board 240 where it may be directed as necessary. The returnground path to the negative electrode of battery 260 includes contactpad 244 b, circuit board clip 274 a, bottom negative contact 274 andspring 272 to negative electrode 264. This circuit is also advantageousin that the circuit needed to power assembled circuit board 240 isprovided completely within battery pack 130 and does not require anexternal circuit path which could add further cost and manufacturingcomplexity.

The high side of the circuit to recharge battery 260 extends frompositive charging ring 190, to coil spring 156, 158, printed circuitboard 148, pin spring 146, contact pin 140, into battery back 130 viaouter bottom ring contact 278, and then through circuit board clip 278a, contact pad 244 c, assembled circuit board 240, contact pad 242 b,circuit board clip 216 a, positive top contact 216, spring 218 andfinally to positive terminal 262 of battery 260. The circuit may thenreturn from negative terminal 264 of battery 260 to spring 272, bottomnegative contact 274 to contact pin 136 via knub 274 b, pin spring 142,circuit board 148, wave springs 150, 158, ground charge ring 192.

When battery pack 130 is installed into battery compartment 127 ofbarrel 124, a completed electrical path for the light source 101 (orelectrical load) may be formed from the positive terminal ofrechargeable battery 260 through the input pad 242 b on assembledcircuit board 240 as described above. The input pad 242 b, whichcorresponds to V_CELL+ in FIG. 7, is coupled to load switches 558, 572(see FIGS. 9B, 9C) on assembled circuit board 240. When load switches558, 572 are closed (or conductive), output pad 242 c on the assembledcircuit board 240 is energized. Because output pad 242 c is coupled tothe top positive central contact 214 b of battery pack 130, currentpasses from top positive central contact 214 b of battery pack 130 topositive contact 133 of lamp module 128 and through the light source.This electrical path then extends from heat sink housing 188 of lampmodule 128 to the outer ring top contact 212 of battery pack 130. Theouter ring top contact 212 of battery pack 130 is electrically coupledto the negative electrode 264 of the rechargeable battery 260 asdescribed above.

FIG. 8 is a block diagram illustrating the relationship of theelectronic circuitry of a preferred embodiment of assembled circuitboard 240 for a portable lighting device such as the flashlightillustrated and discussed in connection with FIGS. 1-7. However, thecircuitry and motion sensitive user interface provided thereby may beemployed in flashlights other than flashlight 100 as well as otherportable lighting devices such head lamps or lanterns. Assembled circuitboard 240 preferably includes charging system 502, battery protectioncircuit 504, MOSFET driver and load switch circuit 506, LDO linearregulator circuit 508, controller circuit 510, accelerometer circuit512, and magnetometer circuit 514. In other embodiments, one or more ofthese components may be omitted if its functionality is not desired inthe particular application of the invention.

As indicated above, the assembled circuit board 240 includes electricalcontacts, preferably in the form of I/O pads. As reflected in thedetailed circuit schematic assembled circuit board 240 shown in FIGS.9A-G, the I/O pads may include +5 VDC 244 c, MOM 244 a, bottom GND 244b, V_CELL+ 242 b, VLOAD 242 c, and top GND 242 a.

FIG. 9A shows a circuit schematic diagram of charging system 502. The +5VDC signal line 516 may be electrically coupled to +5 VDC input pad 244c on assembled circuit board 240 of battery pack 130. As previouslymentioned, the +5 VDC input pad 244 c may be electrically coupled tocharging ring 166. The +5 VDC signal line 516 is coupled to p-channelmetal-oxide-semiconductor field-effect transistor (PMOS) 530.

The gate of PMOS 530 may be coupled to ground so that PMOS 530 may turnon if the +5 VDC I/O pad 516 is coupled to a positive voltage supplysuch as a charging cradle. If the +5 VDC I/O pad 516 is coupled to anegative voltage supply accidentally, such as where flashlight 100 isplaced in the charging cradle in reverse, PMOS 530 will be turned off toprotect the remainder of the circuitry on assembled circuit board 240from reverse polarity damage.

Source 532 of PMOS 530 may be coupled to charge protection circuit 536to provide protection to battery 260 in battery pack 130 from failuresdue to charging circuit 544, which will be described in more detaillater.

Signal line 532 may be coupled to the collector of a bipolar transistor534 while the base of the bipolar transistor 534 may be coupled tosignal line 1_WIRE 630, which in turn is an output of controller circuit510.

Charge protection circuit 536 may include output V_WALL_ADAPTER 538,which may be coupled to charging circuit 544.

Charge protection circuit 536 may be used to continuously monitor inputvoltage +5 VDC 516, the input current, and battery voltage 540. In thecase where an excessive input voltage may be experienced, e.g., whereflashlight 100 is placed in a charging cradle that provides a +12V DCinput, charge protection circuit 536 may remove power from chargingcircuit 536 by turning off an internal switch in charge protectioncircuit 536. In case of an excessive current situation, chargeprotection circuit 536 may limit the system current at a thresholdvalue. If the excessive current situation persists, charge protectioncircuit 536 may switch the pass element OFF after a blanking period.

In a preferred embodiment, a commercially available device, e.g.,BQ24314 manufactured by Texas Instruments, may be used to protectagainst excessive voltage and current, as well as protect the batterycharger front-end.

Charging circuit 544 may be powered by V_WALL_ADAPTER 538 and may beused for charging rechargeable battery 260 located within battery pack130. In charging system 502, charging circuit 544 may includecurrent-sensitive circuitry and thermal-regulation circuitry to limitthe charge current. Charging circuit 544 may have an output, VCHARGE538, which may eventually couple to the positive electrode ofrechargeable battery 260.

In a preferred embodiment, a commercially available stand-alone chargemanager controller, e.g., MCP73832 manufactured by Microchip Technology,may be used.

Signal line DISABLE_CHARGE 624 from controller circuit 510 may be usedto disable charging circuit 544. In this situation, V_WALL_ADAPTER 538displays a high impedance so that flashlight 100 communicates with anexternal charging cradle through signal line 1_WIRE 630 and +5 VDC 516.

Signal line CHG 630 may be used to indicate the charging status whichinformation may be used by controller circuit 514. When an overpowersituation is detected, although charge protection circuit 536 may beused to protect the components on assembled circuit board 240 fromfurther damage, it would be advantageous to transmit this information tothe charging cradle.

In the present embodiment, when an overpower situation is detected,controller 602 may utilize signal line 1_WIRE 630 to send sequentialsignals to the charging cradle as a warning sign. Signal line 1_WIRE 630may be pulled high by controller 602 so that the collector of NPNbipolar transistor 534 may be pulled low. Therefore, signal line 530 aswell as +5 VDC 516 may be pulled low. In accordance, +5 VDC 516 may beconverted from a power input line to a signal output line, from theflashlight's point of view. When a high signal on +5 VDC is desired,signal line 1_WIRE 630 may be pulled low by controller 602 so that thecollector of NPN bipolar transistor 534 as well as signal line 530 willno longer be pulled low. Therefore, controller 602 may treat +5 VDC 616as a serial port for sending a sequence of high or low signals.

The battery voltage may also be monitored by charge protection circuit536 at signal line 540 which is fed back from VCHARGE 548.

Charging systems other than charging system 502 described above may alsobe used.

FIG. 9B shows a circuit schematic diagram of battery protection circuit504. Battery protection circuit 504 may include an input, VCHARGE 548,which extends from charging system 502 in the present embodiment. Thisinput signal line, VCHARGE 548, is coupled to the source of a PMOS 550.The gate of PMOS 550 is coupled to input signal line VCHARGE 548 througha resistor. Also the gate of PMOS 550 may be driven by an internalsignal line CO 564 through an inverter 568. The drain of PMOS 550 may becoupled to a signal line V_CELL+ 522 which may be further coupled to I/Opad V_CELL+ 242 b on assembled circuit board 240. As described above,I/O pad V_CELL+ 242 b is coupled to the positive electrode ofrechargeable battery 260 in the battery pack 130. Signal line V_CELL+522 may also be driven by signal line VCHARGE 548 via a diode 554.

Signal line V_CELL+ 522 is coupled to an input of load switch 553 whilethe output of load switch 558 is coupled to internal voltage supplysignal VBAT 560 which in turn is coupled to the positive contact 133 oflamp module 128 through signal line VLOAD 524 (shown in FIG. 9C) and I/Opad VLOAD 242 c. When a short circuit is detected on the load, forexample, lamp module 128, load switch 558 will turn off to protect thecircuit. In a preferred embodiment, a commercially available loadswitch, e.g., FPF2163 manufactured by Fairchild Semiconductor, may beused.

Voltage protection circuit 562 may be used to further protectrechargeable battery 260 in battery pack 130 from over charging, overdischarging or from excessive current. In one embodiment, a commerciallyavailable voltage protection circuit, e.g., S-8241ABSPG manufactured bySeiko Instruments, may be used.

Battery protection circuits other than battery protection circuit 504described above may also be employed.

FIG. 9C shows a circuit schematic diagram of a preferred MOSFET driverand load switch circuit 506. In the embodiment of FIG. 9C, load switchcircuit 506 is implemented by PMOS 572 which may have a source coupledto the internal voltage supply signal VBAT 560 from battery protectioncircuit 504, and a drain coupled to signal line VLOAD 576. Signal lineVLOAD 524 is coupled to I/O pad VLOAD 242 c of assembled circuit board240. As previously described, the I/O pad VLOAD 242 c is coupled to thetop central contact 214 b of battery pack 130 and may then be coupled tothe compressible positive contact 133 of lamp module 128.

The gate of PMOS 572 may be coupled to a MOSFET driver, which may beimplemented by an NPN bipolar transistor 570. The gate of PMOS 572 mayalso be pulled high to internal voltage supply signal VBAT 560 byresistors. In accordance, when the base of bipolar transistor 570 isdriven high by signal LAMP_DRIVE 624, bipolar transistor 570 conducts asdoes PMOS 572. Therefore, electric power may flow from internal voltagesupply VBAT 560 to voltage output pad VLOAD 242 c to form a portion of acomplete loop of electric current that may turn on lamp module 128.

In other embodiments, controller 510 may directly drive load switch 572.Additionally, other forms of driver circuits may be employed. Similarly,other types of load switches may be employed for load switch 506. Ingeneral, load switch 506 should be an electronic switch of some formsuch as a field effect transistor or a bi-polar junction transistor.

FIG. 9D shows a circuit schematic diagram of a preferred low dropout (orLDO) linear regulator circuit 508. LDO linear regulator circuit 508 mayinclude a low dropout regulator 588, which may be implemented by a DClinear voltage regulator operated with a small input-output differentialvoltage. Signal line 586 forms an output from two diodes 582, 584 whichis driven by signal lines V_WALL_ADAPTER 538 and VBAT 560, respectively.This configuration preferably allows the higher voltage from signallines V_WALL_ADAPTER 538 or VBAT 560 to supply low dropout regulator588.

In a preferred embodiment, the output of low dropout regulator 588 maybe set to +2.8V on output line 590 to be used as a power supply sourceto other components, e.g., controller circuit 514, accelerometer 512,and magnetometer 514. In a preferred embodiment, a commerciallyavailable LDO regulator, e.g., NCP700 manufactured by ON Semiconductor,may be used.

Linear regulator circuits other than linear regulator circuit 508described above may also be employed.

FIG. 9E is a schematic diagram of a preferred controller circuit 510.Controller circuit 510 may include a controller 602 having input andoutput connections. Controller 602 may receive input signals throughsignal lines ADC_DC_XOUT 608, ADC_DC_YOUT 606, ADC_DC_ZOUT 604, ADC_X-G612, ADC_Y-G 614, ADC_Z-G 616, CHG 628 and RESET 634. Controller 602 mayalso deliver output signals through signal lines PD 610, ST 618, SW_ON630, S/R/MOSI 620, LAMP_DRIVE_MISO 622, DISABLE_COMPASS 624,CHARGE_DISABLE 626 and 1_WIRE 630. The power supply VCC (not shown) ofcontroller 602 is supported by the +2.8V power supply signal provided byoutput line 590 of the LDO regulator 508.

In a preferred embodiment, controller 602 is commercially availablemicrocontroller having embedded memory, e.g., ATtiny861 which is an8-bit microcontroller manufactured by Atmel Corporation. In anotherembodiment, controller 602 may be a microprocessor. Yet in otherembodiments, controller 602 may be discrete circuits. Those skilled inthe art will understand that other types of controller circuits may alsobe employed.

FIG. 9F shows a circuit schematic diagram of a preferred exemplaryaccelerometer circuit 512. Accelerometer circuit 512 is preferably a3-axis accelerometer. However, in other embodiments a single axis or atwo axis accelerometer may be used. Accelerometer circuit 512 of thepreferred embodiment includes outputs ADC_X-G 616, ADC_Y-G 614 andADC_Z-G 612 corresponding to signals representing movement in each ofthe x, y, and z directions. These three signals are coupled tocontroller circuit 510 for further processing.

Accelerometer circuit 512 preferably includes an inertial sensor 640that receives information from internal sensing elements and providesanalog signals. In other embodiments inertial sensor 640 may convert theanalog signals it generates to digital signals. Inertial sensor 640 isused in the present embodiment to measure the Earth's staticgravitational field by providing acceleration information in three axes,e.g., mutually orthogonal axes, namely X, Y and Z. The power supply VDDof 3-axis accelerometer circuit 512 may be supported by the +2.8V powersupply signal on output line 590 from LDO regulator 508.

If the Z axis of inertial sensor 640 is pointing towards the center ofthe Earth, then X and Y will have an acceleration of zero. Z, however,will experience an acceleration of −1 G due to the gravity of the Earth.If inertial sensor 640 was flipped 180° so that Z is pointing away fromthe Earth, X and Y will remain at zero, but Z will have an accelerationof +1 G.

Inertial sensor 640 is attached to assembled circuit board 240 so thatthe X, Y and Z axes are fixed relative to flashlight 100. In a preferredembodiment, inertial sensor 640 is oriented on board 240 so that the Yaxis extends along the longitudinal axis of flashlight 100. As such,when flashlight 100 is positioned horizontally, the Y axis also extendshorizontally. In this position, when X and Z are rotated left or rightabout the longitudinal axis of the flashlight 100, corresponding gravityinformation on X and Z will be sent to controller 602 through ADC_X-G616 and ADC_Z-G 612, respectively, as the magnitudes of the accelerationin the X and Z axes change during rotation. Relative angular rotationmay, therefore, be computed by controller 602. Controller 602 may usethe information on ADC_X-G 616 and ADC_Z-G 612 to determine whetherthere is a rotation about the longitudinal axis of flashlight 100, andin which direction.

In a preferred embodiment, the switch for flashlight 100 is located inswitch and tail cap assembly 106. When the switch is initiallyactivated, the starting orientation of the X and Z axes are unknown tocontroller 602. Thus, controller 602 calculates a starting angle orposition based on measurements of the Earth's gravitational field in theX and Z axes in the starting orientation. Once their startingorientation is established, subsequent angular measurements may be madeto track the rotation of flashlight 100. To this end, measurements maybe made to determine whether the angle is increasing or decreasingrelative to the starting orientation so as to calculate rotationalchanges.

In another embodiment, the two axes of the portable lighting device maybe known. For example, in a flashlight with a push button switch, thestarting position of both the X and Z axes would be known, assuming thatthe switch is pointing up as dictated by the shape of a user's hand withthe thumb above the switch. In this case, only one axis (either the X orZ) may be used to calculate rotational changes, and hence a single axisaccelerometer could be used.

In both embodiments above, it is preferred that flashlight 100 bepositioned approximately horizontally for the user to obtain higherresolution when rotating, i.e., better sensing of the rotation of the Xand Z axes. As the Y axis tilts farther from horizontal, rotationalerrors may occur. Thus, in operation, it is preferred that flashlight100 be held to +/−30° from horizontal. If the tilting is greater than30°, it is preferred that the Y axis be monitored and the rotationalinput ignored until flashlight 100 is tilted back within the +/−30°window. In other implementations, however, more sophisticated vectorcalculations may be employed so that the 3 axis are combined such thatthe user's intent may be determined regardless of the horizon.

Inertial sensor 640 may include an input, PD 610, which may be an outputfrom controller circuit 514. PD 610 may be used as an indication thatthere is no need for the inertial sensor 640 to operate by pulling PD610 low. When PD 610 is pulled low, inertial sensor 640 may stay in apower down situation. This configuration may be used to save batterypower. The inertial sensor 640 may also include an input ST 618 whichmay be an output from controller circuit 514 to indicate that aself-test is desired.

In a preferred embodiment, inertial sensor 640 may be a commerciallyavailable microelectro-mechanical systems (MEMS), e.g., LIS394AL, whichis a 3-axis accelerometer manufactured by ST Microelectronics. Thoseskilled in the art will appreciate that other types of inertial sensorcircuits may also be employed.

FIG. 9G shows a schematic diagram of magneto resistive sensor circuit514. Magneto resistive sensor circuit 514 may include inputsCOMPASS_DISABLE 624 and S/R/MOSI 620 which may be outputs fromcontroller circuit 512. Exemplary magneto resistive sensor circuit 514may also include outputs ADC_DC_XOUT 608, ADC_DC_YOUT 606 andADC_DC_ZOUT 604 that may be coupled to controller circuit 512 forfurther processing.

When the input signal COMPASS_DISABLE 624 is driven low, the +2.8V powersupply may be used to support magneto resistive sensor circuit 514. Whencontroller 602 determines that there is no need for magneto resistivesensor circuit 514 to operate, the input signal COMPASS_DISABLE 624 maybe pulled high by controller 602. The +2.8V power supply may then shutdown from supporting magneto resistive sensor circuit 514. Thisconfiguration may be used to save battery power.

A primary component of magneto resistive sensor circuit 514 is amagnetometer 660. Magnetometer 660 may comprise three sets of Wheatstonebridges placed at orthogonal axes to measure direction and magnitude ofthe Earth's magnetic fields in each of the axes and convert thesemeasurements to differential voltage outputs. In other embodiments, asingle or double axis magnetometer may be used.

In a preferred embodiment, the Y-axis is set as the longitudinal axis110 of flashlight 100. In other words, a change in output ADC_DC_YOUT606 may be interpreted as a direction change of the longitudinal axis110 of flashlight 100.

Magnetometer 660 may be a commercially available magnetometer, e.g.,HMC1043 which is a 3-axis magnetometer manufactured by Honeywell.

The power supply (denoted by VB) for the Wheatstone bridges inmagnetometer 660 may be supported by signal line +VCOMPASS 644 which inturn may be derived from the +2.8V power supply signal provided onoutput 590 of the LDO regulator 508. The emitter of a PNP bipolartransistor 642 is coupled to +2.8V 590 power supply while the collectorof bipolar transistor 642 is coupled to signal line +VCOMPASS 644. Thebase of bipolar transistor 642 may be coupled to signal lineCOMPASS_DISABLE 624 which may be an output from controller circuit 512.

The set/reset (SR-) input of magnetometer 660 may be provided by twosources. The first source may be signal line +VCOMPASS 644. The secondsource may be derived from signal line S/R/MOSI 620 which may be anoutput from controller circuit 510. Signal line S/R/MOSI 620 may becoupled to the base of an NPN bipolar transistor 654 having its emittercoupled to ground. Signal line 652, which may be coupled to thecollector of bipolar transistor 654, may also be the second source tothe set/reset (SR-) input of magnetometer 660.

Outputs of magnetometer 660 may be grouped into three sets ofdifferential voltage outputs: OUTX+ 662 and OUTX− 664; OUTY+ 666 andOUTY− 668; and OUTY+ 670 and OUTY− 672, OUTX+ 662, OUTX− 664 may berespectively coupled to the positive and negative inputs of operationalamplifier 682 which may generate an output ADC_DC_XOUT 608 which may becoupled to controller circuit 510 for further processing. OutputADC_DC_XOUT 608 may be fed back to negative input 678 of operationalamplifier 682 through resistor 686 and capacitor 688 connected inparallel. In addition, the positive input of operational amplifier 680may be coupled to a reference voltage REF_COMPASS 646 which may begenerated by a voltage divider from +VCOMPASS 644.

Similarly, the other sets of differential voltage outputs may be used togenerate ADC_DC_YOUT 606 and ADC_DC_ZOUT 604 which may also have asimilar configuration as that of ADC_DC_XOUT 608 which has describedpreviously.

In the embodiments described above, flashlight 100 may be operated as anelectronic compass. In this mode of operation, a visual, audible, ortactile response may be provided depending on which direction flashlight100 points. For example, the lighting intensity (or brightness) of lampmodule 128 of flashlight 100 may be varied depending on the direction inwhich flashlight 100 points. In one embodiment, when flashlight 100 ispointing at magnetic north, the lighting intensity may be brighter,e.g., at a maximum brightness. As the user rotates flashlight 100 eitherclockwise or counter-clockwise towards magnetic south, the lightingintensity may decrease and may be set at a lower level, e.g., minimumbrightness, when pointing due south. In an alternative embodiment, thebrightness levels may be reversed. It is preferred that flashlight 100be kept substantially horizontal, i.e., that rotation of flashlight 100occur about an axis that is substantially vertical to the ground. Inthis manner, flashlight 100 may be used as a compass, and the user maydetermine the directions of due north, due south and directions inbetween based on the varying intensity of the lamp module 128.

In addition to varying the brightness, the lamp module 128 may be madeto blink when flashlight 100 is pointed at or near one or more of north,south, east and west to provide further directional information to theuser. For example, the blink may be programmed to occur when flashlight100 is pointed in a direction that is within a certain angle from north,south, east or west, e.g., within +/−5°.

In addition to the visual responses discussed above, flashlight 100 maybe configured to provide audible or tactile responses in addition to thevisual response or in the alternative. For example, controller 510 maybe programmed to output a certain sequence of beeps or provide beeps ofdifferent tones depending on the direction in which the flashlight ispointing. Further, the flashlight may say “North”, “South”, “East”, or“West” when the flashlight is pointed in those directions. Such audibleresponses would be provided through the audio interface and speaker 518(see FIG. 8), which is in communication with controller 510.

Alternatively, controller 510 may be connected to a vibrator instead ofaudio interface and speaker 518 to provide tactile responses that variesdepending on the direction flashlight 100 is pointing. The vibrator may,for example, be a simple electric motor with an eccentric weight.

As noted above, it is preferred that the user maintain flashlight 100 ina substantially horizontal position while using flashlight 100 as amagnetic compass. If flashlight 100 is not so maintained, an error mayoccur in compass operation. It is preferred that this error may becorrected by measuring the flashlight's angle of tilt by using the Yaxis of accelerometer circuit 512 described previously in connectionwith FIG. 9F, and then using this information to correct the compassoperation. Those skilled in the art will appreciate that other types ofmagneto resistive sensor circuits may be employed.

As indicated above, it is preferred that flashlight may operate inmultiple modes. The operation and accessing of these modes are nowfurther discussed. FIG. 10A is a flow diagram illustrating a preferredmanner of operation 702 in which flashlight 100 may access and performvarious modes.

The user may initially activate switch 168 of flashlight 100 with apress and release sequence as in step 704. Flashlight 100 is thus turnedon in step 706 and may start producing light and may enter a first mode,or mode 1, of operation as in step 708. In a preferred embodiment, thefirst mode of operation 708 may be a normal or standard operating modewhere lamp module 128 provides a steady beam of light.

At this stage, if the user performs another press and release sequenceon switch 168, flashlight 100 may recognize this sequence as a switchoff command 710 and flashlight 100 may be turned off as in step 712. Ifthere has been no switch off command, the user may enter a second modeof operation 718. This may be accomplished by the user rotatingflashlight 100 to the right 714 about its principal axis of projection110 while keeping switch 168 continuously depressed 716.

While flashlight 100 is in the first mode of operation 708 (withoutswitching off 710), if there is no detection of rotation to the right714 along about its principal axis of projection 110, or if there is adetection of right rotation 714 about its principal axis of projection110 but switch 168 is not continuously depressed 716, flashlight 100remains in the first mode of operation 708.

Once flashlight 100 is in the second mode of operation 718, it may beswitched off with another press and release sequence as in step 720. Ifflashlight 100 is not turned off, but is instead rotated right 722 aboutits principal axis of projection 110 while switch 168 is continuouslydepressed 724, flashlight 100 may enter into a third mode of operation.In FIG. 10A, this is represented by mode N 726. This represents thatflashlight 100 may preferably follow the foregoing sequence to accessany number of operating modes. But in a preferred embodiment, there arefive modes of operation.

While flashlight 100 is in the second mode of operation 718 (withoutswitching off 720), if there is no detection of right rotation 722 alongits principal axis of projection 110, or if there is a detection ofright rotation 722 about its principal axis of projection 110 but switch168 is not continuously depressed 724, flashlight 100 remains in thesecond mode of operation 718.

When flashlight 100 is in the last mode of operation 726 it may beswitched off 728 with a press and release sequence. When flashlight 100is in the last mode of operation (without switching off 728), ifflashlight 100 is rotated right 730 about its principal axis ofprojection 110 while switch 168 is continuously depressed 732,flashlight 100 may return back to the first mode of operation 708.

When flashlight 100 is in the last mode of operation 726 (withoutswitching off 728), if there is no detection of right rotation 730 aboutits principal axis of projection 110, or if there is a detection ofright rotation 730 about its principal axis of projection 110 but switch168 is not continuously depressed 732, flashlight 100 remains in thelast mode of operation 726.

Therefore, in a preferred embodiment, flashlight 100 may enteradditional modes of operation by rotating right about its principal axisof projection 110 while keeping switch 168 continually depressed. Thisoperation allows flashlight 100 to enter into a new mode of operationwithout using the sequence of pressing and releasing of a switch button.

While there are various modes of operation that are within the scope ofthe current invention, in a preferred embodiment, steady lighting withvariable brightness may be set as the first mode of operation 708. Ablinking lighting with variable brightness may be set as the second modeof operation 718. Other modes of operation may include an SOS mode withvariable brightness, a motion sensitive signal mode, an electroniccompass mode and a night light mode. These modes of operation may beassigned in an arbitrary order or as the user desires. To that end, ifthe user believes he or she will use a certain mode or modes more oftenthan others, the user may set the first few modes accordingly.

As previously described in connection with FIG. 9F, 3-axis accelerometercircuit 512 may include outputs ADC_X-G 616, ADC_Y-G 614 and ADC_Z-G612, that may be coupled to controller circuit 510. Accelerometercircuit 512 may be mounted on assembled circuit board 240 with itsY-axis pointing along the longitudinal axis of flashlight 100.Therefore, when flashlight 100 is placed horizontally, if flashlight 100is rotated clockwise or counter-clockwise along the longitudinal axis offlashlight 100, the magnitudes of the acceleration in the X and Z axiswould be changed, and the gravity information on X and Z may be sent tocontroller 602 through ADC_X-G 616 and ADC_Z-G 612, respectively.Controller 602 may use the information on ADC_X-G 616 and ADC_Z-G 612 todetermine whether there is a rotation along the longitudinal axis offlashlight 100. Therefore, flashlight 100 may use the rotation about itslongitudinal axis (or the information change on ADC_X-G 616 and ADC_Z-G612) as a command decision point so as to determine whether to enterinto a new mode of operation or not.

The operation flow 702 shown in FIG. 10A may be implemented by softwarestored in memory on controller 602. Controller 602 may thus beprogrammed to control the sequence of operation based on signalsreceived from the outputs of 3-axis accelerometer circuit 512. In otherwords, when controller 602 receives information from ADC_X-G 616 andADC_Z-G 612, controller 602 may change its sequence of execution basedon the information received from the outputs of 3-axis accelerometercircuit 512.

Controller 602 may also be programmed to control the flow of electricalpower through lamp module 128 based on signals received from the outputsof 3-axis accelerometer circuit 512. That is, when controller 602receives information on ADC_X-G 616 and ADC_Z-G 612, controller 602 maychange some of its output signals based on the execution of softwarestored in controller 602. For example, controller 602 may pull itsoutput signal LAMP_DRIVE 624 to a high state so that bipolar transistor570 and PMOS 572 conduct. In this manner, electric power may flow frominternal voltage supply VBAT 560 to voltage output pad VLOAD 576 to forma portion of a loop of electrical current that may be used to turn onlamp module 128.

Those skilled in the art will appreciate that the flow diagram 702 inFIG. 10A is an example only, and that other types of operation can alsobe employed. For example, the command for entering into a new mode ofoperation may be implemented when flashlight 100 is rotated left aboutits principal axis of projection 110 while keeping switch 168 depressed.

Alternatively, other types of movement of flashlight 100 by the userthat may cause a change in outputs ADC_X-G 616, ADC_Y-G 614 or ADC_Z-G612 of 3-axis accelerometer circuit 512 may also be used for flashlight100 to enter into a new mode of operation.

Examples of different modes of operation contemplated by the currentinvention, as well as how each mode may be adjusted, are now morespecifically described with reference to FIGS. 10B-10I. Those skilled inthe art will appreciate that modes of operation beyond those describedabove are within the scope of the invention.

FIG. 10B is a flow diagram illustrating an electronic compass operation740 that may be performed by flashlight 100. As previously described inconnection with FIG. 10A, flashlight 100 may perform a plurality ofmodes of operation. It is preferred that flashlight 100 may switch fromone mode of operation to another by rotating flashlight 100 about itsprincipal axis of projection 110 while switch 168 is continuouslydepressed. When flashlight 100 has entered into the electronic compassmode 742, the light source of flashlight 100 may initially produce asteady standard stream of light.

Following the steps of operation 740, flashlight 100 may be turned off712 by a designated method, e.g., the user performs a switch off command744 such as a press and release of switch 168.

While flashlight 100 is in the electronic compass mode 742 (withoutswitching off 744), if flashlight 100 is rotated right 746 about itsprincipal axis of projection 110 while switch 168 is continuouslydepressed 748, flashlight 100 may enter into the next mode of operation750.

The next mode of operation may be designated as any one of the followingexamples: a steady lighting with variable brightness, a blinkinglighting with variable brightness, an SOS mode with variable brightness,a motion sensitive signal mode or a night light mode. Alternatively, thenext mode 750 may be different than those listed above.

The user may remain in the electronic compass pass mode 742 as follows.If there is no detection of right rotation 746 about its principal axisof projection 110, or if there is a detection of right rotation 746about its principal axis of projection 110 but switch 168 is notcontinuously depressed 748, flashlight 100 may remain in the electroniccompass mode 742.

In step 752, the compass mode may provide a blinking capability to alertthe user that the flashlight is pointed at or near any of the fourcardinal magnetic coordinates, i.e., north, south, east or west. To helpdescribe this feature, it should be noted that flashlight 100 generallyhas a midpoint or centerpoint along its longitudinal axis. And if avertical axis is extended through this midpoint, flashlight 100 may berotated by the user about this centerpoint. In other words, flashlight100 may have a rotating center. Here, if flashlight 100 is rotated aboutthis centerpoint, or rotated around its rotating center, so that itslongitudinal axis is pointing in a direction that falls within a 10°angle with one of the cardinal magnetic coordinates 752, flashlight 100will blink. In other embodiments, this blink may occur if flashlight 100is pointed in a direction that is within 5° on either side of thecardinal magnetic coordinate. The user is thus alerted that he or she isgenerally facing a cardinal magnetic coordinate. The included angularrange within which a blink is superimposed may also be an angular rangeother than +/−5°.

Another feature within compass mode 742 is also available with thecurrent invention. While flashlight 100 is rotated about its center, ifthe front end of flashlight 100 is facing toward the Earth's magneticnorth as in step 756, lamp module 128 may get brighter as in step 758,e.g., it may attain its brightest setting. Conversely, while flashlight100 is rotated about its center so that its front end is facing towardthe Earth's magnetic south as in step 760, lamp module 128 may be setdimmer 762, e.g., to its dimmest setting.

In another embodiment, flashlight 100 may be programmed oppositely. Thatis, while flashlight 100 is rotating around its center, if the front endof flashlight 100 is facing toward the Earth's magnetic south, lampmodule 128 may get brighter. And while flashlight 100 is rotated aroundits rotating center, if the front end of flashlight 100 is facing towardthe magnetic north of the Earth, Lamp module 128 can be set dimmer.

As previously described in connection with FIG. 9G, a preferred magnetoresistive sensor circuit 514 may include a magnetometer 660 which mayproduce output signals ADC_DC_XOUT 608, ADC_DC_YOUT 606 and ADC_DC_ZOUT604 that may be coupled to controller circuit 512.

When the longitudinal axis of flashlight 100 is horizontal and rotatedaround its center, the values on ADC_DC_YOUT 606 will be changed if thelongitudinal axis 110 of flashlight 100 is changed because the Y-axis isset to be coincident with the longitudinal axis 110 of flashlight 100.

The other two outputs ADC_DC_XOUT 608 and ADC_DC_ZOUT 604 could bechanged when the longitudinal axis 110 of flashlight 100 is changeddepending on their vector components projected on the horizontal plane.Since flashlight 100 may be rotated about its longitudinal axis, eitherthe X-axis or Z-axis may point toward the Earth. When this occurs, thevector component projected on the horizontal plane for that axis is zeroand the output of that axis would not have any change when flashlight100 is placed horizontally and rotated around the rotating center. Ifnone of the X-axis or Z-axis is facing toward the Earth, then, outputsof both X-axis and Z-axis can be changed when flashlight 100 is placedhorizontally and rotated around the rotating center depending on theirvector components projected on the horizontal plane. The magneticinformation would be sent to controller 602 through ADC_DC_YOUT 606,ADC_DC_XOUT 608 and ADC_DC_ZOUT 604.

Controller 602 may use information on ADC_DC_YOUT 606, ADC_DC_XOUT 608and ADC_DC_ZOUT 604 to determine whether and how much of a rotationflashlight 100 had made around its rotating center. Therefore,flashlight 100 may use the rotation around its rotating center (or theinformation on ADC_DC_YOUT 606, ADC_DC_XOUT 608 and ADC_DC_ZOUT 604) todetermine the brightness on lamp module 128 or whether a blink on lampmodule 128 is required.

The brightness on lamp module 128 may be determined by changing the dutycycle on lamp module 128 with a frequency that is higher than a human'seye can detect. A duty cycle on lamp module 128 may be produced by asequence of high and low states on LAMP_DRIVE 624 signal, which isdriven by controller 602. This sequence of high and low states on signalLAMP_DRIVE 624, together with other components on the load electricalpath, may cause bipolar transistor 570 and PMOS 572 to be conductive andnon-conductive alternately. As the percentage of cycle time that theswitch conducts increases, lamp module 128 will become brighter. On theother hand, as the percentage of cycle time that the switch conducts isreduced, lamp module 128 will become dimmer. Methods of adjustingbrightness of the light source other than through modulating the dutycycle may also be used, including, for example, adjusting the voltage,current, and/or power delivered to the light source.

The operation flow 740 shown in FIG. 10B may be implemented by softwarestored in the memory of controller 602. Controller 602 may be programmedto control the flow of electrical power through lamp module 128 based onsignals received from outputs of magneto-resistive sensor circuit 514.When controller 602 receives information on ADC_DC_YOUT 606, ADC_DC_XOUT608 and ADC_DC_ZOUT 604, controller 602 may change some of its outputsignals, e.g., LAMP_DRIVE 624, based on the execution of software storedin controller 602.

FIG. 10C is a flow diagram illustrating an exemplary motion sensitiveoperation 770 of a preferred flashlight 100.

When flashlight 100 has entered into the motion sensitive signal mode772, information on a default intensity may be loaded from memory 774for controller 602 to provide a control signal to control the brightnesson lamp module 128. In the present embodiment, the memory may be anEEPROM embedded in controller 602. The default intensity information maybe a predetermined setting, for example the minimum intensity.Alternatively, the default intensity information may be the intensity ofthe last usage before flashlight 100 is turned off. Other intensitiesmay be predetermined.

As previously described in connection with FIG. 10A, flashlight 100 mayperform a plurality of modes of operation. It is preferred thatflashlight 100 may switch from one mode of operation to another byrotating flashlight 100 about its principal axis of projection 110 whileswitch 168 is continuously depressed. After the default intensityinformation is loaded from memory 774, if flashlight 100 is rotatedright 778 about its principal axis of projection 110 while switch 168 iscontinuously depressed 776, flashlight 100 may enter into the next modeof operation 780.

The next mode of operation can be designated as one of the followingexamples: a steady lighting with variable brightness, a blinkinglighting with variable brightness, an SOS mode with variable brightness,an electronic compass mode or a night light mode.

On the other hand, if switch 168 is released 782, the motion sensitivesignal operation may be performed by detecting whether there is a leftrotation 784 along the principal axis of projection 110 of flashlight100. If a left rotation 784 is detected, then flashlight 100 can beturned on 786. If the flashlight 100 is turned back to the previousposition, then flashlight 100 can be turned of 788. In other words,flashlight 100 can be toggled between on and off by rotating it left andthen rotating it back.

Flashlight 100 may be turned off 712 by a designated method. Forexample, if switch 168 is depressed and then released, flashlight 100may recognize this sequence as a switch off command 790 and flashlight100 will be turned off 712.

FIG. 10D is a flow diagram illustrating a preferred variable brightnessmode of operation 802 for flashlight 100.

When flashlight 100 has entered into the variable brightness mode 804, adefault intensity information may be loaded from a memory 806 forcontroller 602 to provide a control signal to control the brightness onlamp module 128. In a preferred embodiment, the memory may be an EEPROMembedded in controller 602. The default intensity information may be apredetermined setting, for example, the maximum intensity.Alternatively, the default intensity information can be the intensity ofthe last usage before flashlight 100 is turned off. Other intensitiesmay be predetermined.

After the default intensity information is loaded from memory 806, ifflashlight 100 is rotated right 810 about its principal axis ofprojection 110 while switch 168 is continuously depressed 808,flashlight 100 can enter into the next mode of operation 812.

The next mode of operation can be designated as one of the followingexamples: a motion sensitive signal mode, a blinking light with variablebrightness, an SOS mode with variable brightness, an electronic compassmode or a night light mode.

If flashlight 100 is rotated left 814 about its principal axis ofprojection 110 while switch 168 is still continuously depressed 808, theamount of rotation can be calculated by controller 602 and theflashlight brightness may be varied based on the calculated amount ofrotation 816. In a preferred embodiment, before the flashlight 100 isrotated, the flashlight brightness is set to the maximum, while when theflashlight 100 is rotated left 45° and beyond, the flashlight brightnessis set to the minimum. In other words, when the flashlight 100 isrotated left from 0° to 45°, the flashlight brightness can changelinearly from maximum to minimum.

If a suitable brightness is found while flashlight 100 is rotating left814, the switch 168 may be released 818 and the brightness existing atthat time may be stored in a memory 820. Flashlight 100 may retain thatlevel of brightness until it is turned off.

Flashlight 100 may be turned off 712 by a designated method. Forexample, if switch 168 is depressed and then released, flashlight 100may recognize this sequence as a switch off command 822 and flashlight100 will be turned off 712.

FIG. 10E is a flow diagram illustrating a preferred SOS mode ofoperation 832 of the exemplary flashlight 100. The exemplary SOS mode ofoperation 832 may be similar to the preferred variable brightness modeof operation 802 shown in FIG. 10D. A difference between the two may bethat while in the SOS mode of operation 832, an SOS code may begenerated instead of steady brightness.

FIG. 10F is a flow diagram illustrating an exemplary variable blinkingrate mode of operation 862 of the exemplary flashlight 100.

When flashlight 100 has entered the variable blinking rate mode 864, adefault blinking rate information may be loaded from memory 866 forcontroller 602 to provide a control signal to control the blinking rateon lamp module 128. In a preferred embodiment, the memory may be anEEPROM embedded in controller 602. The default blinking rate informationmay be a predetermined setting, for example, the maximum blinking rate.Alternatively, the default intensity information can be the blinkingrate of the last usage before flashlight 100 is turned off. Otherpredetermined settings may be used.

After the default blinking rate information is loaded from memory 866,if flashlight 100 is rotated right 870 about its principal axis ofprojection 110 while switch 168 is continuously depressed 868,flashlight 100 may enter into the next mode of operation 872.

The next mode of operation may be designated as one of the followingexamples: a motion sensitive signal mode, a steady lighting withvariable brightness, an SOS mode with variable brightness, an electroniccompass mode or a night light mode.

If flashlight 100 is rotated left 874 about its principal axis ofprojection 110 while switch 168 is still continuously depressed 868, theamount of rotation may be calculated by controller 602 and theflashlight blinking rate may be set based on the calculated amount ofrotation 816. In a preferred embodiment, before flashlight 100 rotated,the flashlight blinking rate is set to the maximum, while when theflashlight 100 is rotated left 45° and beyond, the flashlight blinkingrate is set to the minimum. In other words, when the flashlight 100 isrotated left from 0° to 45°, the flashlight blinking rate may changelinearly from maximum to minimum.

It is desirable that the highest blinking rate be set to a value that isdetectable by a human eye, for example, a 4 blinks per second rate canbe predetermined as the maximum blinking rate, while a 0.5 blinks persecond rate can be predetermined as the minimum blinking rate. Otherblinking rates may be set.

If a suitable blinking rate is determined while flashlight 100 isrotating left 874, the switch 168 may be released 878 and the determinedblinking rate may be stored in a memory 880. Flashlight 100 may keep thedetermined blinking rate until it is turned off.

Flashlight 100 may be turned off 712 by a designated method. Forexample, if switch 168 is depressed and then released, flashlight 100may recognize this sequence as a switch off command 882 and flashlight100 will be turned off 712.

As previously described in connection with FIG. 9F, 3-axis accelerometercircuit 512 has outputs, ADC_X-G 616, ADC_Y-G 614 and ADC_Z-G 612, thatare also coupled to controller circuit 510. Accelerometer circuit 512may be mounted on the assembled circuit board 240 with its Y-axisextending along the longitudinal axis of flashlight 100. Therefore, whenflashlight 100 is placed horizontally, if flashlight 100 is rotatedclockwise or counter-clockwise along the longitudinal axis of flashlight100, the magnitudes of the acceleration in the X and Z axis may bechanged, and the gravity information on X and Z may be sent to thecontroller 602 through ADC_X-G 616 and ADC_Z-G 612, respectively.Controller 602 may use information on ADC_X-G 616 and ADC_Z-G 612 todetermine whether there is rotation about the longitudinal axis 110 offlashlight 100. Flashlight 100 may use the rotation about itslongitudinal axis (or the information on the change in ADC_X-G 616 andADC_Z-G 612) as a status to decide whether a condition exists to changeto a different feature within the same mode of operation.

The variable brightness on lamp module 128 may be determined by changingthe duty cycle on lamp module 128 with a frequency that is higher than ahuman's eye can detect. A duty cycle on lamp module 128 may be producedby a sequence of high and low states on the LAMP_DRIVE 624 signal, whichis driven by controller 602. This sequence of high and low states onsignal LAMP_DRIVE 624, together with other components on the electricalload path may cause bipolar transistor 570 and PMOS 572 to be conductiveand non-conductive alternately. If the time period of conductive islonger, lamp module 128 is brighter. On the other hand, if the timeperiod of conductive is shorter, lamp module 128 is dimmer.

The variable blinking rate on lamp module 128 can also be determined bychanging the duty cycle on lamp module 128 but with a frequency that isdetectable by a human's eye. The circuits that supports the variableblinking rate can be the same as that supports variable brightnessdescribed previously.

As a combination, the SOS mode with variable brightness or a blinkinglighting with variable brightness on lamp module 128 may be produced bymaking a duty cycle on lamp module 128 with a frequency that isdetectable by a human's eye. During the low cycle, lamp module 128 isoff while during the high cycle, lamp module 128 can have a duty cyclewith a frequency that is higher than a human's eye can detect. In otherwords, there is a high frequency duty cycle within the high period of alow frequency duty cycle. This function can be performed by controller602.

The operation flow 770 shown in FIGS. 10C-10F can be implemented bysoftware stored in a memory of controller 602. Thus, controller 602 canbe programmed to control the sequence of operation based on signalsreceived from the outputs of 3-axis accelerometer circuit 512. Whencontroller 602 receives information from ADC_X-G 616 and ADC_Z-G 612 the3-axis accelerometer circuit 512, controller 602 may change its sequenceof execution based on such information.

Controller 602 may also be programmed to control the flow of electricalpower through lamp module 128 based on signals received from the outputsof 3-axis accelerometer circuit 512. When controller 602 receivesinformation from ADC_X-G 616 and ADC_Z-G 612, controller 602 may changesome of its output signals based on the execution of software stored inthe controller 602.

Those skilled in the art will appreciate that the flow diagramsillustrated FIG. 10C-10F are examples, and that other types ofoperations may also be employed. For example, the condition for turningoff flashlight 100 may occur when flashlight 100 is rotated left aboutits principal axis of projection 110 while keeping switch 168 depressed.And the condition for turning on flashlight 100 may occur whenflashlight 100 is rotated right about its principal axis of projection110 while keeping switch 168 depressed. Also, the variability feature inthe variable brightness mode, variable blinking rate mode or SOS modewith variable brightness may be obtained by rotating flashlight 100 inan opposite direction as illustrated in FIGS. 10C-10F.

Other types of movements of flashlight 100 that may cause a change inthe outputs of the 3-axis accelerometer circuit 512 may also be used asa command for flashlight 100 to change features. Accordingly, thecurrent invention is not limited to the movements described herein forinterfacing with controller 602.

FIG. 10G is a flow diagram showing a preferred night light operation 900of flashlight 100. As previously described in connection with FIG. 9,flashlight 100 may preferably operate in a plurality of modes, andflashlight 100 may switch from one mode of operation to another byrotating flashlight 100 about its principal axis of projection 110 whileswitch 168 is continuously depressed. When flashlight 100 has enteredinto the night light mode 902, the light source of flashlight 100 may beset to a steady lighting.

Flashlight 100 may be turned off 712 by a designated method. Forexample, if switch 168 is depressed and then released, flashlight 100may recognize this sequence as a switch off command 904 and flashlight100 may be turned off 712.

While flashlight 100 is in the night light mode 900 (without switchingoff 904), if flashlight 100 is rotated right 906 about its principalaxis of projection 110 while switch 158 is continuously depressed 908,flashlight 100 may enter into the next mode of operation 910.

The next mode of operation may be designated as one of the followingexamples: a steady lighting with variable brightness, a blinkinglighting with variable brightness, an SOS mode with variable brightness,an electronic compass mode or a motion sensitive signal mode.

While flashlight 100 is in the night light mode 900 without switchingoff 904, if there is no detection of right rotation 906 about itsprincipal axis of projection 110 or if there is a detection of rightrotation 906 about its principal axis of projection 110 but switch 168is not continuously depressed 908, flashlight 100 remains in the nightlight mode 900. A timer may be reset 912 to allow a user to change intoa new mode of operation if desired. If there is no indication ofchanging into a new mode of operation before the timer is expired 914,flashlight 100 may start the night light function by setting flashlight100 to the lowest brightness 916. In a preferred embodiment, the timermay be set to expire in 30 seconds at which point flashlight 100 maygradually dim until reaching its lowest brightness. In anotherembodiment, flashlight 100 may dim and eventually turn completely off.Once flashlight 100 starts operating in the night light mode, it maycontinuously provide the lowest (or other pre-set) brightness untilflashlight 100 detects a bump 918 at which point flashlight 100 may beset to the highest (or other) brightness 920 and the routine goes backto step 904.

In operation, when a user plans to sleep in a dark environment, he/shemay set flashlight 100 to night light mode 902. In response, flashlight100 will dim to a predetermined brightness level after a set time, suchas 30 seconds. Preferably the brightness level is set at a very lowlevel, such as 5 to 10% of its normal duty cycle, so that the powerdrain on the battery is extremely low. Despite the low power output, theflashlight will remain visible so that the user can easily locate it ina dark environment. When the user needs flashlight 100, all he or sheneeds do is move flashlight 100 and the detection of this movement byflashlight 100 may immediately turn flashlight 100 to its highest (orother pre-set) brightness. The user may then have a predefined window,such as 30 seconds, to turn off flashlight 100 or make flashlight 100enter into a new mode of operation.

The 30 second time period may be adjusted and other time periods, forexample, one minute, may be employed.

As previously described in connection with FIG. 9F, 3-axis accelerometercircuit 512 has outputs ADC_X-G 616, ADC_Y-G 614 and ADC_Z-G 612 thatmay also be coupled to controller circuit 510. Accelerometer circuit 512may be mounted on assembled circuit board 240 with its Y-axis extendingalong the longitudinal axis of flashlight 100. When flashlight 100 is ina horizontal position, if flashlight 100 is rotated clockwise orcounter-clockwise about its longitudinal axis 110, the magnitudes of theacceleration in the X and Z axes may change, and the gravity informationon X and Z may be sent to controller 602 through ADC_X-G 616 and ADC_Z-G612, respectively. Controller 602 may use information from ADC_X-G 616and ADC_Z-G 612 to determine whether there is a rotation about thelongitudinal axis 110 of flashlight 100. Flashlight 100 may detect abump or rolling (or the information change on ADC_X-G 616 and ADC_Z-G612) and use this information to determine whether flashlight 100 shouldremain as a night light.

The brightness on lamp module 128 may be determined by changing the dutycycle on lamp module 128 to a frequency above which a human eye maydetect. A duty cycle on lamp module 128 may be produced by a sequence ofhigh and low states on the LAMP_DRIVE 624 signal which is driven bycontroller 602. This sequence of high and low states on signalLAMP_DRIVE 624, together with other components on the load electricalpath, may cause bipolar transistor 570 and PMOS 572 to be conductive andnon-conductive alternately. When the percentage of conduction time ineach cycle is at 100%, lamp module 128 will be at its brightest. On theother hand, as the percentage of conduction time in each cycleapproaches 0%, lamp module 128 will be at its lowest brightness.

The operation flow 900 shown in FIG. 10G may be implemented by softwarestored in a memory of controller 602. Controller 602 may be programmedto control the sequence of operation based on signals received fromoutputs of 3-axis accelerometer circuit 512. When controller 602receives information from ADC_X-G 616 and ADC_Z-G 612 of the 3-axisaccelerometer circuit 512, controller 602 may change its sequence ofexecution based on the information.

Controller 602 may also be programmed to control the flow of electricalpower through lamp module 128 based on signals received from outputs of3-axis accelerometer circuit 512. When controller 602 receivesinformation from ADC_X-G 616 and ADC_Z-G 612, controller 602 may changesome of its output signals based on the execution of software stored incontroller 602.

FIG. 10H is a flow diagram illustrating a preferred adjustable mode ofoperation 922 of flashlight 100. As previously described in connectionwith FIG. 10A, flashlight 100 preferably operates in a plurality ofmodes and flashlight 100 may switch from one mode of operation toanother by rotating flashlight 100 about the principal axis ofprojection 110 while switch 168 is continuously depressed. However, someusers are right-handed while some are left-handed. Therefore, it isdesired that the direction of rotation of flashlight 100 about itsprincipal axis of projection 110 may be set by a user according to theprocedure 922 shown in FIG. 10H.

After flashlight 100 is switched on 924 by a press and release sequenceon switch 168, the light source of flashlight 100 may start producinglight 926 and flashlight 100 may enter into a first mode of operation708.

If the principal axis of projection 110 is pointed up 928 in asubstantially vertical direction while switch 168 is continuouslydepressed 930, flashlight 100 may be set to a right-handed mode 932. Ifthe principal axis of projection 110 is pointed down 934 in asubstantially vertical direction while switch 168 is continuouslydepressed 936, flashlight 100 may be set to a left-handed mode 938 ofoperation. The controller may also be configured so that if it receivesa predefined command, either through the tail cap switch or via themotion sensitive user interface, the controller will return to defaultsettings provided during manufacturing.

The foregoing adjustments may be accomplished by other methods. Forexample, a right-handed mode may be set by pointing down flashlight 100while switch 168 is continuously depressed, or by pointing flashlight100 up while rotating flashlight 100 right about its principal axis ofprojection 110.

In a preferred embodiment, when in the right-handed mode 932, a new modeof operation may be entered by rotating flashlight 100 right about itsprincipal axis of projection 110 while switch 168 is continuouslydepressed. Also when in the right-handed mode, the feature brightnessmay be varied in different modes by rotating the flashlight 100 leftabout its principal axis of projection 110. This may occur, for example,to vary the brightness in the steady lighting mode, the blinking lightmode or the SOS mode. When in the left-handed mode 938, the foregoingresults may be achieved by rotating flashlight 100 about its principalaxis 100 in the opposite direction as in the right-handed mode 932.

Alternatively, other types of movements of flashlight 100 that may causea change in outputs ADC_X-G 616, ADC_Y-G 614 or ADC_Z-G 612 of 3-axisaccelerometer circuit 512 may also be used as a command for flashlight100 to adjust the user's mode.

As previously described in connection with FIG. 9F, 3-axis accelerometercircuit 512 may include outputs ADC_X-G 616, ADC_Y-G 614 and ADC_Z-G 612that may be coupled to controller circuit 510. Accelerometer circuit 512may be mounted on assembled circuit board 240 with its Y-axis extendingalong the longitudinal axis of the flashlight 100. When flashlight 100is pointed up vertically, the magnitude of the acceleration in the Yaxis would be −1 G. When flashlight 100 is pointed down vertically, themagnitude of the acceleration in the Y axis would be +1 G. The gravityinformation on Y may be sent to controller 602 through ADC_Y-G 614.

Controller 602 may use the information on ADC_Y-G 614 to determinewhether flashlight 100 is pointing up or down to determine whether aleft- or right-handed user mode is desired.

The operation flow 922 shown in FIG. 10H may be implemented by softwarestored in the memory of controller 602. Controller 602 may be programmedto control the sequence of operation based on signals received from theoutputs of 3-axis accelerometer circuit 512. When controller 602receives information from ADC_Y-G 614 of 3-axis accelerometer circuit512, controller 602 may change a user's preference (or parametersetting) based on this information.

Although the previous description in determining whether flashlight 100is pointed vertically involves the information from outputs ADC_X-G 616,ADC_Y-G 614 and ADC_Z-G 61 from 3-axis accelerometer circuit 512, it iscontemplated that outputs ADC_DC_XOUT 608, ADC_DC_YOUT 606 andADC_DC_ZOUT 604 from the magneto resistive sensor circuit 514 may alsobe used to determine whether flashlight 100 is pointing vertically.

As previously described in connection with FIG. 9G, the preferredmagneto resistive sensor circuit 514 may include a magnetometer 660which may produce output signals ADC_DC_XOUT 608, ADC_DC_YOUT 606 andADC_DC_ZOUT 604 that may also be coupled to controller circuit 512. Whenflashlight 100 is placed vertically, the values from ADC_DC_YOUT 606 maybe zero because in the present embodiment, the Y-axis may be set toincident the longitudinal axis of flashlight 100. This information maybe combined with other conditions to determine which user's mode isdesired.

FIG. 10I is a flow diagram illustrating a preferred automatic turn offoperation 942 of flashlight 100. As previously described in connectionwith FIG. 10A, it is preferred that flashlight 100 may operate in aplurality of modes. While flashlight 100 is in any mode of operation, ifthe automatic turn off feature is enabled 944, flashlight 100 may accessthe automatic turn off routine 942.

Flashlight 100 may be turned off 712 by a designated method. Forexample, if the switch 168 is depressed and then released, flashlight100 may recognize this sequence as a switch off command 946 andflashlight 100 will be turned off 712.

While the automatically turned off feature is enabled 944 withoutswitching off 946, if flashlight 100 is not moved 948, a timer may bereset 950 for automatically turning off flashlight 100 after a certainamount of time. When this timer lapses 952, flashlight 100 may beautomatically turned off 954. Before the timer expires, however anymovement on flashlight 100 may cause the timer to reset.

In preferred embodiment, the timer may be set to be expire in 5 minutes.However, the timer may be set to expire at other times, e.g. 10 minutes.

The expiration time may comprise a software timer implemented by asoftware program, e.g., a counting routine, executed by controller 602.Alternatively, the timer may comprise a hardware timer implemented byelectronic circuits.

Flashlight 100 may be automatically turned off when there is inactivity,e.g., no movement on flashlight 100 for a period of time. Battery powermay thus be saved by this automatic turn off feature. In a preferredembodiment, the automatic turn off feature may be activated ordeactivated by the user.

As previously described in connection with FIG. 9F, 3-axis accelerometercircuit 512 may include outputs, ADC_X-G 616, ADC_Y-G 614 and ADC_Z-G612 that may also be coupled to controller circuit 510. Accelerometercircuit 512 may be mounted on assembled circuit board 240 with itsY-axis extending along the longitudinal axis 110 of flashlight 100. Whenflashlight 100 is positioned horizontally, if flashlight 100 is rotatedclockwise or counter-clockwise about its longitudinal axis 110 themagnitudes of the acceleration in the X and Z axes may change, and thegravity information on X and Z may be sent to controller 602 throughADC_X-G 616 and ADC_Z-G 612 respectively. Controller 602 may use theinformation from ADC_X-G 616 and ADC_Z-G 612 to determine whether thereis a rotation about the longitudinal axis 110 of flashlight 100. In thismanner, flashlight 100 may detect movement (or the information change onADC_X-G 616 and ADC_Z-G 612) and use this information to determinewhether the timer should be reset.

The operation flow 942 shown in FIG. 10I may be implemented by softwarestored in the memory of controller 602. Controller 602 may be programmedto control the sequence of operation based on signals received fromoutputs of 3-axis accelerometer circuit 512. That is, when controller602 receives information from ADC_X-G 616 and ADC_Z-G 612 of 3-axisaccelerometer circuit 512, controller 602 may change its sequence ofexecution based on the information.

Controller 602 may be programmed to control the flow of electrical powerthrough lamp module 128 based on signals received from the outputs of3-axis accelerometer circuit 512. That is, when controller 602 receivesinformation on ADC_X-G 616 and ADC_Z-G 612, controller 602 may changesome of its output signals based on the execution of software stored incontroller 602.

FIG. 10J is a flow diagram showing a preferred night light mode offlashlight 100. Flashlight 100 may preferably operate in a plurality ofmodes, and may enter night light mode 902 as discussed above. Flashlight100 may be turned off 712 by a designated method. For example, if switch168 is depressed and then released, flashlight 100 may recognize thissequence as a switch off command 904 and turn flashlight 100 off 712.

While flashlight 100 is in the night light mode 1110, without switchingoff 904, if flashlight 100 is rotated right 906 about its principal axis110 while switch 168 is continuously depressed 908, flashlight 100 mayenter into the next mode of operation 910. The next mode of operationmay be those discussed above, or other modes.

While flashlight 100 is in the night light mode without switching off904, if there is no detection of right rotation 906, or if there is adetection of right rotation but switch 168 is not continuously depressed908, flashlight 100 remains in the night light mode. A reset timerfunction 912, 1112 may be experienced. In the case of reset timer 1112,if the flashlight is tilted up 45 degrees followed by a tilted backmovement 1116, and if the momentary switch is continuously depressed1118, the timer may be incrementally increased. If not, the timer mayexpire 914 and the flashlight may gradually dim to the lowest brightness916, or some other brightness. Thereafter, if a bump is detected 918,the flashlight may be set to the highest brightness 920, or some otherbrightness.

FIG. 10K is a flow diagram for beginning a left or right configuration1132, i.e., left or right handed operation. Here, if flashlight 100 isturned on 1134, and flashlight 100 is tilted down, then tilted up andthen tilted down, and the momentary switch 168 is continuously depressed1138, and if the momentary switch 168 is then released 140, flashlight100 may toggle between a right-hand user mode and a left-hand user mode1142, in configuration 1144. In other embodiments, flashlight 100 may beambidextrous.

Another preferred flashlight embodiment 300 is now described withreference to FIG. 11. As shown, flashlight 300 generally includes barrel324, head assembly 104 located at the forward end of barrel 324, andswitch and tail cap assembly 306 located at the rear end of barrel 324.The head assembly 104 is disposed about the forward end of the barrel324, and the switch and tail cap assembly 306 encloses the aft end ofbarrel 324.

FIG. 12 is a partial cross-sectional view of flashlight 300 of FIG. 11taken along the plane indicated by 302-302. FIG. 13 is an enlargedpartial cross-sectional view of the forward section of flashlight 300 ofFIG. 11 taken through the plane indicated by 302-302. (The portions ofFIGS. 12, 13 that relate to the battery cassette 330 are not shown incross-section.) FIG. 15A is an exploded perspective view of headassembly 104, barrel 324 and other components of flashlight 300 of FIG.11.

Referring to FIGS. 13 and 15A, head assembly 104 may generally includecombined head and face cap 112, lens 116, reflector 118, retainingcollar 120, shoulder ring 126, lamp module 128, lower insulator 129 ando-rings 114, 122. Head assembly 104 and components including combinedhead and face cap 112, lens 116, reflector 118, retaining collar 120,shoulder ring 126, lamp module 128, lower insulator 129 and o-rings 114,122 have been fully described in connection with FIGS. 3, 5A, 20, 21Aand 21B.

Other configurations of the head assembly 104 may also be used. Forexample, in other embodiments, head assembly 104 may form a part of amechanical switch means to provide a user interface.

Referring to FIG. 13, lamp module 128 is electrically coupled toflashlight 300 as follows. Flashlight 300 of the present embodimentincludes a battery cassette 330 that includes positive electrode 454which is electrically coupled to compressible positive contact 133 oflamp module 128. After the current passes through the light source, aground connection extends from the negative electrode of the lightsource through heat sink housing 188, which acts as the negative contactof lamp module 128, and shoulder ring 126, which in turn is electricallycoupled to barrel 324. The ground path continues to inner tail capsection 364, wave spring 150, and to circuit board 348 which includes anegative contact that is coupled to a negative electrode on batterycassette 330 thereby completing the circuit.

In the present embodiment, barrel 324 is used as a portion of the groundpath from the negative contact of lamp module 128 to the negativeelectrode of battery cassette 330. As previously described in connectionwith FIGS. 3 and 5A.

Referring to FIGS. 13 and 15A, the forward region 189 of shoulder ring126 includes a plurality of splines 193 (best seen in FIG. 15A) that arepreferably spaced equally around the circumference of a portion of theforward region 189 of shoulder ring 126 so as to generally extend in theaxial direction of the shoulder ring 126. The outer diameter of theforward region 189 of shoulder ring 126 is dimensioned so that it willprovide an interference fit with the inner wall of the forward portion325 of barrel 324 and so that splines 193 will cut into the inner wallof the forward portion 325 of barrel 324 when shoulder ring 126 is pressfitted into the forward portion 325 of the barrel 324.

When shoulder ring 126 is press fitted into the forward portion 325 ofbarrel 324, the splines 193 will splay and cut into metal on the innerdiameter of the forward portion 325 of barrel 324. Annular reliefgrooves are provided adjacent the forward and aft ends of splines 193 onshoulder 126 to receive metal from barrel 324 that is displaced duringthe press fitting operation. In this way, shoulder ring 126 ispermanently locked in metal to metal contact with the forward portion325 of barrel 324.

Splines 193 can cut through any anodized coating provided on theinterior of barrel 324, thereby providing the possibility of using thebarrel as a ground path without having to make a skin cut to removeanodizing or mask the contacting area before an anodizing treatment ashas been conventionally required with aluminum flashlights.

FIG. 14 is an enlarged partial cross-sectional view of the rearwardsection of flashlight 300 of FIG. 11 taken through the plane indicatedby 302-302. (In FIG. 14, however, battery cassette 330 is not shown incross-section.) The rearward section of flashlight 300 generallycomprises switch and tail cap assembly 306. FIG. 15B is an explodedperspective view of switch and tail cap assembly 306.

Referring to FIGS. 14 and 15B, switch and tail cap assembly 306 of thepresent embodiment preferably includes snap ring 132, lower switchhousing 334, contact pins 338, 340, contact pin springs 344, 346,circuit board 348, wave spring 150, snap dome 152, actuator 354, upperswitch housing 360, lip seal 162, inner tail cap section 364, switchport seal 168, and outer tail cap section 170.

Lower switch housing 334 may be similar to lower switch housing 134 asdescribed above in connection with FIG. 4. To this end, lower switchhousing 334 may also include three cylindrical channels and chambers.However, in the present embodiment, only the inner two channels areprovided with contact pins 338, 340 to slide in and out of the frontsurface of lower switch housing 334. Contact pin springs 344, 346 may beinstalled in the two chambers and may in turn engage a shoulder oncontact pins 338, 340 as shown. Springs 344, 346 serve to push contactpins 338, 340 forward until their respective shoulders engage the endwall of its respective chamber. Contact pins 338, 340 and contact insprings 344, 346 are preferably made out of metal so as to form part ofthe electrical paths described later. In the present embodiment, contactpins 338, 340 may comprise a metal, such as, aluminum while contact pinsprings 344, 346 may comprise a spring, such as, music wire.

The channels of lower switch housing 334 are configured to align withcontacts on the bottom of battery cassette 330. When battery cassette330 is installed, contact pin 338 may be aligned and make contact withthe bottom central contact (4.5 VDC) of battery cassette 330, andcontact pin 340 may be aligned and make contact with the bottom outerring (GND) of battery cassette 330. Both contacts are shown in FIG. 17.

Circuit board 348 preferably includes contacts on both sides. Circuitboard 348 may also include conductive vias routed through board 348 tocouple the contacts on opposite sides. Alternatively, wires may berouted around board 348 to couple contacts on opposite sides. Circuitboard 348 may also include electronic components installed thereon. Theforward side of circuit board 348 (which is facing the lower switchhousing 334) includes two contacts (labeled GND and 4.5 VDC as shown inFIG. 17) that are electrically couple to contact pin springs 344, 346,respectively. The rear side of circuit board 348 (which is facing theupper switch housing 360) includes three contact pads that correspond toGND, MOM and 4.5 VDC and that are located at designated locations. Eachpair of the corresponding contacts on the front side and rear side ofcircuit board 348 may be electrically connected through conductive viasprovided in circuit board 348, or alternatively routing wires. Theelectronic components and their function assembled on circuit board 348will be described later in this specification.

Upper switch housing 360 includes a cylindrical channel that allowsactuator 354 to slide within. An annular rim of switch port seal 168 isheld between an annular lip 399 of outer tail cap 170, which is locatedat the rear end of flashlight 300, and inner tail cap section 364. Whena user presses on switch port seal 168, actuator 354 is moved forwardand engages snap dome 152 to close a switch formed by snap dome 152 andtwo contact pads on circuit board 348. When the user releases switchport seal 168, the switch is open.

In the present embodiment, upper switch housing 360 and actuator 354preferably comprise a non-conductive material, such as plastic. Switchport seal 168 also preferably comprises a non-conductive material, suchas rubber. Snap dome 152 preferably comprises a conductive material suchas metal. Other suitable materials may be used.

In the present embodiment, snap ring 132 is placed between the frontedge of lower switch housing 334 and inner tail cap section 364 toprevent lower switch housing 334 from moving forward.

Wave spring 150 may be provided between the rear edge of circuit board348 and inner tail cap section 364 to provide a compressible springcontact between the two. Wave spring 150 also applies a biasing force tocircuit board 348, which in turn applies the biasing force to lowerswitch housing 334, thereby serving to press cover switch housing 334against snap ring 132.

Inner tail cap section 364 preferably includes threads 365 on the frontouter surface of inner tail cap section 364 for mating with threads 329on the rear inner surface of barrel 324.

In the present embodiment, the outer diameter of the aft end of innertail cap section 364 and the inner diameter of the outer tail capsection 170 are preferably sized so that tail cap 170 may be permanentlypress fitted onto the aft end of inner tail cap section 364 therebyforming an integral switch and tail cap assembly 306.

Inner tail cap section 364 preferably comprises a conductive materialsuch as aluminum. Inner tail cap section 364 may also be nickel plated.

A one-way valve, such as a lip seal 162, may be provided at theinterface between barrel 324 and the switch and tail cap assembly 306 toprovide a watertight seal while simultaneously allowing overpressurewithin the flashlight to expel or vent to atmosphere. However, otherforms of sealing elements, such as an o-ring, may be used instead ofone-way valve 162 to form a watertight seal. Lip seal 162 is preferablymade out of non-conductive material, such as rubber.

Other configurations of switch and tail cap assembly 306 may be used.For example, the switch function may be included in a side, push buttonswitch or in an internal rotating head assembly switch such as thatemployed in U.S. patent application Ser. No. 12/353,396, filed Jan. 14,2009.

Referring now to FIGS. 15A, 16A, 16B and 17, the battery cassette 330 isnow further described. As mentioned above, battery cassette 330preferably contains the batteries used to power the flashlight 300 orother lighting device. After the batteries are inserted into batterycassette 330, it may be inserted into flashlight barrel 324 along withthe other components of flashlight 300 as shown in FIGS. 15A and 15B.

As shown in FIG. 16A, battery cassette 330 may include front or lamp endhousing assembly 410 and rear or tail end housing assembly 430. Thesetwo housings may be held together by center connector 450 as both shownin FIG. 16B which is an exploded view of the components comprisingcassette 330.

As also shown in FIG. 16B, front or lamp end housing assembly 410 mayinclude front housing 411 which may be formed in a configuration toinclude prongs 411 a, 411 b, 411 c. Front housing assembly 410 may alsoinclude positive lamp contact 412, which itself includes tab 415, whichin turn includes flaps 413 a, 413 b, 413 c, 413 d. Flaps 413 are sizedso that hole 414 preferably exists in the center thereof. As discussedlater, these tabs are in electrical contact with center connector 450.Front housing assembly 410 may also include front crossover contact 414and spring 416. Contacts 412, 414 and spring 416 preferably comprise anelectrical conducting material.

Front housing assembly 410 is preferably manufactured in a manner thatreduces the number of steps needed to assemble its components. To thisend, front housing 411 may be injection molded from a plastic or othersuitable material. This injection molding process preferably includesthe co-molding of positive lamp contact 412 and front crossover contact414 with housing 411. That is, contacts 412, 414 are preferablypositioned within the injection molding machine so that they becomeencompassed or otherwise held in place by the injected material as itsolidifies. They are located in the injection molding machine so thatthey end up being in the appropriate positions to form parts of theelectrical path as described later. In this manner, separatemanufacturing steps whereby contacts 412, 412 would be attached tohousing 411 may be avoided.

Though co-molding is preferred other means may be used to assemblecontacts 412, 414 with housing 411. After housing 411 and contacts 412,414 are co-molded or otherwise assembled, spring 416 may be press fitinto housing 411 so that it is in contact with front crossover contact414. For example, spring 415 may be press into a recess between housingprongs 411 a, 411 b. Though this recess is not shown in FIG. 16B,similar recesses 439 are shown in rear housing 431. In any event, othermeans may be used to assemble spring 416 with housing 411.

Rear or tail end housing assembly 430 may include rear housing 431 whichmay be formed in a configuration to include prongs 431 a, 431 b, 431 cthat correspond to front housing prongs 411 a, 411 b, 411 c when the twohousing assemblies 410, 430 are coupled together. Rear housing 430 mayalso include rear crossover contact 432, outer ring contact 434 andsprings 417, 418. Contacts 432, 434 and springs 437, 438 preferablycomprise an electrical conducting material.

Rear housing assembly 430 may be manufactured similarly to front housingassembly 410 so as to reduce the number of assembly steps. That is, rearcross contact 432 and outer ring contact 434 may be co-molded along withrear housing 431 during an injection molding process so that they areappropriately located to form parts of the electrical paths as discussedlater. Though co-molding is preferred, other means may be used toassemble contacts 432, 434 with rear housing 431.

Springs 437, 438 may then be press fit into rear housing 431 so thatthey are in electrical contact with contacts 432, 434, respectively. Forexample, spring 437, 438 may be press fit into recesses 439 in housing431. Other means may be used to assemble springs 437, 438 with housing431.

As shown in FIG. 16A, front and rear housing assemblies 410, 430 arecoupled to one another to form cassette 330. To facilitate thiscoupling, as shown in FIG. 16B, front housing 411 may include pin 419 onprong 411 c that may engage hole 436 formed in prong 431 c of rearhousing 431. Similarly, back housing 431 may include pins 437 on prongs431 a, 431 b that may engage holes (not shown) in prongs 411 a, 411 b offront housing 411.

Both housings 411, 431 preferably include a central hole 452 throughwhich center connector 450 may extend. Center connector 450 preferablyholds housings 411, 431 together and also comprises part of theelectrical path. Center connector may include rear disk or contact 451.To combine housings 411, 431, they may first be placed together bycorresponding pins and holds, and center connector may then be slidthrough the center holes 452. Tab 413 of positive lamp contact 412 mayreside at the forward end of central hole 452 in front housing 411. Tab413 may include flaps 413 a, b, c, d. Flaps 413 are preferably flexibleso that when center connector is pushed through housings 411, 431, andthrough hole 415, its forward end 454 may protrude through hole 415 andpush flaps 413 forward until rear contact 451 engages the rear surfaceof rear housing 431. The center connector 450 is then held in place by afriction fit with flaps 413 a, b, c, d which are bent in a forwardposition.

The current invention's use of pins and holes to readily couple housingassemblies 410, 430 along with pushing the center connector 450 throughthe central holes 452 represents an advance over earlier systems thatuse threads as the means to couple different parts of a device intendedto house batteries. That is, housing assembly 410, 430 may simply bepressed on to each other and held in place by center connector 450without having to screw on one housing to another. This preferably easesmanufacturing.

Though the figures show corresponding pronged housing assemblies 410,430, the current invention is not limited to this embodiment. Otherconfigurations for the housing assemblies may be used. To this end,other housing configurations for front and rear housings 411, 431 may beused but it is preferred that any alternate housings have correspondingconfigurations so that they may be joined together to form cassette 330that may contain batteries.

When housings 410, 430 are joined together to form cassette 330 as shownin FIG. 16A, the housing prongs 411, 431 come together to form batterybays 462, 464, 466. More specifically, battery bay 462 is formed betweenprongs 411 c/431 c and 411 a/431 a, bay 464 is formed between prongs 411a/431 a and 411 b/431 b and bay 466 is formed between prongs 411 b/431 band 411 d/431 c. These bays are preferably sized to receive the desiredsize battery, e.g., AAA battery or other size. As shown in FIG. 16B, thecross section of the prongs is preferably curved so that the batteriesmay fit snugly in each bay. FIG. 16A shows battery 426 a in bay 462, andbattery 466 a in bay 466.

Each bay preferably includes electrical contacts to engage the positiveand negative ends of a battery. For example, battery bay 462 may includepositive lamp contact 412 to engage the positive terminal of battery 462a, and spring 437 and rear crossover contact 432 to engage the negativeterminal of battery 462 a As such, in bay 462, the positive end ofbattery 462 a is directed to the front of the cassette 330.

Rear crossover contact 432 preferably includes tab 432 a which extendsto battery bay 464 and may serve as the contact to the positive end ofthe battery located in bay 464. Front crossover contact 414 and spring416 may engage the negative terminal of the battery in bay 464. As such,the positive end of battery 464 a directed to the rear of cassette 330.

Front crossover contact 414 may include tab 414 a which extends to bay466 where it may engage the positive terminal of battery 466 a locatedtherein. The negative terminal of battery 466 a in bay 466 may beengaged by spring 438 which is coupled to outer ring contact 434.Accordingly, the positive end of battery 466 a is directed to the frontof cassette 330.

The manner in which cassette 330 may contain the batteries is nowfurther described. As shown in FIG. 16A, battery 462 a is housed in bay462, battery 464 a is housed in bay 464 and battery 466 a corresponds tothe battery housed in bay 466. As shown in FIG. 17, the batteries 462 a,464 a, 466 A are electrically connected in series. However, thebatteries are physically located side by side or in parallel relative toeach other in their respective bays as shown in FIG. 16A. (it should benoted that FIG. 17 is more directed to showing the electrical conductivepath between the batteries and does not show the contemplated physicallocation of the batteries.)

This battery arrangement is advantageous in that the power provided bythree batteries may be attained without having to physically locate themend to end as with many other flashlights having a series electricalconnection. This provides the benefit that the length of the flashlightbarrel or other lighting device housing need not be dictated by thenumber of batteries mounted end to end. More specifically, for example,a flashlight with a certain number of batteries may be shorter which maybe advantageous in certain applications.

The electrical conductive path of the batteries in cassette 330 is nowfurther described starting with battery 462 a. The negative terminal ofbattery 462 a is coupled to the positive terminal of battery 464 athrough spring 437 and then rear crossover contact 432 and tab 432 a.(In FIG. 17, reference numerals 437, 432 and 432 a represent theelectrical path provided by these component as opposed to physicallyshowing them.) The negative terminal of battery 464 a is coupled to thepositive terminal of battery 466 a through spring 416 and then frontcrossover contact 414 and tab 414 a. The negative terminal of battery466 a is coupled to spring 438 and then outer ring contact 434.

As shown in FIG. 17, the positive terminal of battery 462 a iselectrically coupled to center connector 450 via positive lamp contact412 with its tab 413 and flaps 413 a-d. The electrical conductive paththen continues through center connector 450 to its forward end 454 tothe positive electrode of the lamp module 128 as represented by thedotted line 461. (It should be noted that a bulb may also be used.) Fromthe lamp module 128 or other lighting device, the conductive path maythen continue through components of the flashlight that form part of theconductive electrical path as represented by the dotted line 463 in FIG.17. In one embodiment, the dotted line may comprise the flashlight'sbarrel 324. And from there, the conductive path may extend through tailcap 364 and to circuit board 348

As shown in FIG. 17, circuit board 348 may be coupled to two contactpins 338, 340 which are electrically coupled to battery cassette 330 asrepresented by the dotted lines 465, 467. The positive connectionbetween battery cassette 330 and circuit board 348 occurs throughcontact 451 of center connector 450.

As such, center connector 450 provides a positive contact at both endsof cassette 330, i.e., the positive contact at its forward end 454 tolamp module 128 and the positive contact at contact 451 to circuit board348. The negative connection between battery cassette 330 and circuitboard 348 occurs through outer ring contact 434.

When battery cassette 330 is installed into battery compartment 327, inthe present embodiment, an electrical path for the light source (orelectrical load) may be formed from the central electrode or forward end454 of center connector 450 of battery cassette 330 to the compressiblepositive contact 133 of lamp module 128, and then from heat sink 188 oflamp module 128 to the conductive inner surface of barrel 324, then fromrear thread 329 on barrel 324 to thread 365 on conductive inner tail capsection 364 and conductive inner tail cap section 364 itself, thenthrough wave spring 150 to the ground pad on the rear side of circuitboard 348, then to a load switch on circuit board 348, ground pad on thefront side of circuit board 348, contact pin spring 346, contact pin 340and then finally to the negative electrode 434 of battery cassette 330.

As noted above, the positive terminal of battery 462 a may beelectrically coupled to the front of cassette 330. However, the positiveend of battery 462 may also be electrically coupled to the rear ofcassette again through its connection with center connector 450. Thatis, center connector extends to its rear contact 451 at the rear ofcassette 330.

FIG. 18 is a block diagram illustrating electronic components of anexemplary circuit board 348 for a flashlight such as that illustratedand discussed in connection with FIGS. 11-17. The circuit board 348 mayinclude voltage regulator circuit 1004, load switch circuit 1006,controller circuit 1008, and 3-axis accelerometer circuit 1010.

The circuit board 348 may include I/O pads to engage external devices.I/O pads may include top +4.5 VDC 1012, bottom +4.5 VDC 1014, GND 1016,LED_OUT 1018 and SWITCH 1020.

The I/O pads top +4.5 VDC 1012 and GND 1016 may be coupled to thecentral contact 451 and the outer ring contact 434 of battery cassette330, respectively. I/O pads bottom +4.5 VDC 1014 and SWITCH 1018 may becoupled to snap dome 152. When a user presses on switch port seal 168,actuator 354 may be pushed forward to engage snap dome 152 to close theswitch between SWITCH 1020 and +4.5 VDC 1012. When the user releasesswitch port seal 168, the switch is open and SWITCH 1020 is no longercoupled to +4.5 VDC 1012.

Detailed electrical circuit schematics of an embodiment of circuit board348 are shown in FIGS. 19A-D.

FIG. 19A shows a circuit schematic diagram of a preferred voltageregulator circuit 1004. Voltage regulator circuit 1004 may include a lowdropout regulator 1020, which may be implemented by a DC linear voltageregulator operated with a small input-output differential voltage.Signal line 1022 is an output from two diodes 1024, 1026 which may bedriven by signal lines SWITCH 1014 and SW_ON 1046, respectively. Thisconfiguration preferably allows the higher voltage from signal linesSWITCH 1014 or SW_ON 1046 to enable dropout regulator 1020.

In a preferred embodiment, the output of low dropout regulator 1020 maybe set to +3.3V 1028 for use as a power supply source to othercomponents, for example, controller circuit 1008. In one embodiment, acommercial stand-alone LDO regulator, e.g., ISL9003AIRUNZ manufacturedby Intersil Coperation, may be used. It should be understood that othertypes of linear regulator circuits may also be employed.

The voltage supply level from battery (i.e. +4.5 VDC 1012) may bemonitored by controller circuit 1008 through signal line ADC_VBAT 1032.Signal line ADC_VBAT 1032 may be generated by a voltage divider from+4.5 VDC 1012.

The I/O pad SWITCH 1014 may be used to generate signal MOM 1048 forsending to controller circuit 1008 as an indication that a user ispressing on switch port seal 168 when MOM 1048 is low. MOM 1048 may begenerated by NPN bipolar transistor 1052.

FIG. 19B is a circuit schematic diagram of a preferred controllercircuit 1008. Controller circuit 1008 may include controller 1030 withinput and output connections. Controller 1030 may receive input signalsthrough signal lines ADC_VBAT 1032, Z-VOUT 1034, Y-VOUT 1036, X-VOUT1038, SCK 1040, MISO 1042, MOM 1048 and RESET 1050. Controller 1030 mayalso deliver output signals through signal lines LOAD_ENABLE 1044 andSW_ON 1046. The power supply of controller 1030 may be supported by the+3.3V 1028 power supply.

In one embodiment, controller 1030 is a commercially availablecontroller having embedded memory, e.g., an ATtiny24 which is an 8-bitcontroller manufactured by Atmel Corporation. In another embodiment,controller 1030 may be a microprocessor. Yet in other embodiments,controller 1030 may be discrete circuits. Those skilled in the art willappreciate that other types of controller circuits may also be employed.

FIG. 19C shows a circuit schematic diagram of a preferred load switchcircuit 1006. In the embodiment of FIG. 19B, the load switch may beimplemented by NMOS 1054. The source of PMOS 1054 may be coupled to topGND 1016 while the drain of NMOS 1054 may be coupled to LED_OUT 1018.The gate of NMOS 1054 may be coupled to LOAD_ENABLE 1044. Electric powermay flow from LED_OUT 1018 to GND 1016 to form a portion of a loop ofelectrical current that may turn on lamp module 128.

Those skilled in the art will appreciate that other types of driver andload switch circuits can also be employed.

FIG. 19D shows a circuit schematic diagram of a preferred 3-axisaccelerometer circuit 1010. 3-axis accelerometer circuit 1010 mayinclude outputs Z-VOUT 1034, Y-VOUT 1036 and X-VOUT 1038 that may alsobe coupled to the controller circuit 1008 for further processing.

3-axis accelerometer circuit 1010 preferably includes an inertial sensor1058 that may receive information from its internal sensing elements andthat may provide analog signals according to the measurements from theinternal sensing elements. Inertial sensor 1058 may be used to measurethe Earth's static gravity field by providing acceleration informationin three axes, e.g., mutually orthogonal axes, namely X, Y and Z. Thepower supply VDD of 3-axis accelerometer circuit 1010 may be supportedby the +3.3V 1028 power supply.

If the Z axis of inertial sensor 1058 is pointing towards the center ofthe Earth, then X and Y have an acceleration of zero. Z, however, willexperience an acceleration of −1 G due to the gravity of the Earth. Ifinertial sensor 640 was flipped 180° so that Z is pointing away from theEarth, X and Y will remain at zero, but Z will have an acceleration of+1 G.

Inertial sensor 1058 may be attached to circuit board 348 so that the X,Y and Z axes are fixed relative to flashlight 300. In a preferredembodiment, interial sensor 1058 is oriented on board 348 so that the Zaxis extends along the longitudinal axis of flashlight 300. As such,when flashlight 300 is positioned horizontally, the Z axis also extendshorizontally. In this position, when X and Y are rotated left or rightabout the longitudinal axis of the flashlight 300, as the magnitudes ofthe acceleration in the X and Y axes change during rotation, gravityinformation on X and Y may be sent to controller 1030 through X-VOUT1038 and Y-VOUT 1036, respectively. Relative angular rotation may becomputed by controller 1030. Controller 1030 may use the information onX-VOUT 1038 and Y-VOUT 1036 to determine whether there is a rotationabout the longitudinal axis of flashlight 300.

In a preferred embodiment, the switch for flashlight may be located inswitch and tail cap assembly 106. In this arrangement, the startingorientation of the X and Y axes are unknown, so a starting may becalculated based on the Earth's gravitational field in the X and Y axesin the starting orientation. Once their starting orientation isestablished, subsequent angular measurements may be made to track therotation of flashlight 300.

In another embodiment, the switch can be placed on the barrel. In thisarrangement, the starting position of the X and Y axes are known,assuming that the switch is pointing up as dictated by the shape of auser's hand with the thumb above the switch. In this case, only one axis(either the X or Y) may be used to calculate rotational changes.

In both embodiments above, it is preferred that flashlight 300 bepositioned approximately horizontally for the user to obtain higherresolution when rotating, i.e., better sensing of the rotation of the Xand Y axes. As the Z axis tilts farther from horizontal, rotationalerrors may occur. In operation, it is preferred that flashlight 300 beheld to +/−a30° from horizontal. If the tilting is greater than 30°, itis preferred that the Z axis be monitored and the rotational inputignored until flashlight 300 is tilted back within the +/−30° window.

In a preferred embodiment, inertial sensor 1058 may be a commerciallyavailable microelectro-mechanical systems (MEMS), e.g., LIS394AL whichis a 3-axis accelerometer manufactured by ST Microelectronics. Thoseskilled in the art will appreciate that other types of inertial sensorcircuits may also be employed.

The operational functions provided by the exemplary flashlight 300 canbe similar to that described previously in connection with FIGS. 10A and10C-10I. In accordance, detailed descriptions would not be providedherewith.

Alternative preferred embodiments are now described below with referenceto FIGS. 21-37. The embodiments described below share certain featuresthat are similar to the foregoing embodiment. So as noted above, tofacilitate the description, any reference numeral representing anelement in one figure generally represents the same element in otherfigures.

Exemplary flashlights 2100, 2300 are described in connection with FIGS.21-25B and 26-33, respectively. Each of the exemplary flashlights 2100,2300 incorporate a number of distinct aspects. While these distinctaspects have all been incorporated into flashlights 2100, 2300 invarious combinations, the scope of the present invention is notrestricted to flashlights 2100, 2300. Rather, the present invention isdirected to each of the inventive features of flashlights 2100, 2300described below both individually as well as in various combinations.Further, as will become apparent to those skilled in the art afterreviewing the present disclosure, one or more aspects of the presentinvention may also be incorporated into other portable lighting devices,including, for example, head lamps and lanterns.

FIG. 21 shows an exemplary flashlight 2100. The exemplary flashlight2100 generally includes barrel 2124, head assembly 2104 located at theforward end of barrel 2124, and switch and tail cap assembly 2106located at the rear end of barrel 2124. The head assembly 2104 isdisposed about the forward end of the barrel 2124, and the switch andtail cap assembly 2106 encloses the aft end of barrel 2124.

Barrel 2124 may include a textured surface 2108 along a portion of itslength for a user to grip. In the present embodiment, textured surface2108 may be provided by broaching. Alternatively, textured surface 2108may comprise a knurled or machine surface. Any desired pattern may beused for textured surface 2108.

FIG. 22 is a partial cross-sectional view of flashlight 2100 of FIG. 1taken along the plane indicated by line 102-102. FIG. 23 is an enlargedpartial cross-sectional view of a forward section of flashlight 2100 ofFIG. 21 taken through the plane indicated by line 102-102. (The portionsof FIGS. 22-24 that relate to the battery pack 2130 are not shown incross-section.)

Referring to FIGS. 22 and 23, a light source 101 is mounted to theforward end of the barrel 2124. In the present embodiment, the lightsource 101 is mounted so that it is disposed at the aft end of reflector2118. In other embodiments, the reflector 2118 may be omitted, or itsshape changed.

Barrel 2124 is a hollow, tubular structure suitable for housing aportable source of power, such as, for example, rechargeable batterypack 2130. Thus, barrel 2124 serves as a housing for receiving aportable source of power having a positive and a negative electrode orterminal.

In the illustrated embodiment, barrel 2124 is sized to accommodatebattery pack 2130, which contains a single Li-Ion battery cell. In otherembodiments, however, the battery pack 2130 may be omitted and thebarrel 2124 sized to accommodate one or more alkaline dry cell orrechargeable batteries of desired size and capacity. Further, if aplurality of batteries is employed, depending on the implementation, thebatteries may be connected electrically in parallel or series. Othersuitable portable power sources, including, for example, high capacitystorage capacitors may also be used.

In the illustrated embodiment, barrel 2124 includes a forward portion2125 that extends beneath combined head and face cap 2112 so that theouter surface of the head assembly 2104 is generally flush with that ofthe barrel 2124. The inner diameter of the forward portion 2125 issmaller than the inner diameter of the rest of barrel 2124. Also, theouter diameter of at least a portion of the forward portion 2125 may besmaller than the outer diameter of the rest of barrel 2124, so that whenflashlight 2100 is assembled, the outer portion of combined head andface cap 2112 and the outer portion of barrel 2124 may form asubstantially uniform, cylindrical surface, Alternatively, the combinedhead and face cap 2112 and barrel 2124 may have different shapes.

Barrel 2124 is preferably made out of aluminum, but other suitable metalor non-metal (e.g. plastic) materials may also be used. Although barrel2124 is preferably made out of aluminum, in the embodiment of flashlight2100 described below, barrel 2124 is not used as an electrical path forconnecting either the light source 101 or circuit board 2148 to thebattery pack 2130. As a result, barrel 2124 does not form part of themain power circuit for either the light source 101 or circuit board2148. In other embodiments, however, the barrel 2124 may comprise partof the main power circuit for light source 101 and/or circuit board2148, such as where one or more batteries are used in place of batterypack 2130. In such embodiments, barrel 2124 and other componentspreferably comprise a conductive material forming a conductive path.

In the illustrated embodiment, barrel 2124 includes external threads 174formed on the outer diameter of the forward portion 2125, internalthreads 2139 formed on the inner diameter of the forward portion 125,and internal threads 131 formed on the inside diameter of its aft end(best seen in FIG. 24). The barrel 2124 of the present embodiment alsoincludes an annular shoulder 182 formed at the aft end of the forwardportion 125. Annular shoulder 182 acts as a stop for shoulder ring 2126disposed in the forward end of barrel 2124.

FIG. 25A is an exploded perspective view of head assembly 2104, barrel2124, lamp module 2128, and battery pack 2130 of flashlight 2100 of FIG.21. Referring to FIGS. 23 and 25A, head assembly 2104 of the presentembodiment includes combined head and face cap 2112, lens 116, andreflector 2118. In other embodiments, however, head and face cap 2112may comprise two or more separate component parts that may be assembledtogether, for example, with mating threads.

The internal surface of combined head and face cap 2112 may be used tohouse certain components, including, for example, lens 116 and reflector2118. Reflector 2118 and lens 116 are operatively mounted to the innerdiameter of the combined head and face cap 2112. In the presentembodiment, reflector 2118 includes spring clips 2177 extending from itsfront end and distributed evenly around the outer circumference ofreflector 2118 so that reflector 2118 may snap into a correspondingannular recess 2117 formed near the forward end of the inner portion ofcombined head and face cap 2112. In the present embodiment, six springclips 2177 are employed. Other embodiments, however, may employ adifferent number of spring clips 2177 or another means altogether forattaching reflector 2118 to combined head and face cap 2112.

An annular shoulder 119 is provided at the aft end of annular recess2117 to attach reflector 2118 to the combined head and face cap 2112once spring clips 2177 expand into annular recess 2117.

Lens 116 is interposed between a forward facing flange of reflector 2118and a lip 113. In this manner, reflector 2118 and lens 116 are lockedwithin the combined head and face cap 2112. In one implementation, asealing element, such as an o-ring 114, may be located at the interfacebetween the lens 116 and lip 113. Other water resistant means, such as aone-way valve, may also be used. O-ring 114 may comprise rubber or othersuitable material.

An annular groove 115 may be provided in the head and face cap 2112 sothat it is disposed at the interface between the lens 116 and lip 113.The annular groove 115 is preferably sized to partially receive o-ring114, thereby properly positioning o-ring 114 during the assemblyprocess.

Reflector 2118 may include fins 2176 distributed around the outerperimeter of reflector 2118 to provide structural integrity to reflector2118 and to help properly align reflector 2118 within the internalsurface of the head and face cap 2112 and the forward portion 2125 ofbarrel 2124. In the present embodiment, three fins 2176 are employed. Inother embodiments, a different number of fins 2176 may be used, or nofins at all may be used.

Combined head and face cap 2112 may include internal threads 172configured to engage with external threads 174 on the forward portion2125 of barrel 2124. In other implementations, however, other forms ofattachment may be adopted. Further, combined head and face cap 2112 ispreferably made from anodized aluminum, though other suitable materialsmay also be used.

As best seen in FIGS. 23 and 25A, the reflective profile 2121 of thereflector 118 is preferably a segment of a computer-generated optimizedparabola that is metallized for reflectivity and to ensure highprecision optics. Preferably the profile 2121 is defined by a parabolahaving a focal length of less than 0.080 inches, and more preferablybetween 0.040-0.050 inches. Further, the distance between the vertex ofthe parabola defining the profile 2121 and the aft opening of thereflector 121 is preferably 0.070-0.120 inches, more preferably0.075-0.085 inches. The opening of the forward end of the reflector 2118preferably has a diameter of 0.8-0.9 inches, more preferably 0.850-0.852inches, and the opening of the aft end of the reflector 2118 preferablyhas a diameter of 0.2-0.3 inches, more preferably 0.240 to 0.250 inches.Further, the ratio between the distance from the vertex to the openingof the aft end of the reflector 2118 and the focal length is preferablyin the range of 1.5:1 and 3.5:1, more preferably 1.6:1 to 1.8:1.Moreover, the ratio between the distance from the vertex to the openingof the forward end of the reflector 2118 and the focal length ispreferably in the range of 20:1 and 35:1, more preferably 20:1 to 21:1.

Reflector 2118 preferably comprises an injection molded plastic, thoughother suitable materials may be used.

Referring back to FIG. 23, although the embodiment disclosed hereinillustrates a substantially planar lens 116, the flashlight 2100 mayinstead include a lens that has curved surfaces to further improve theoptical performance of the flashlight 2100. For example, the lens mayinclude a biconvex profile or a plano-convex profile in the whole orpart of the lens surface.

Referring to FIGS. 23 and 25A, a sealing element 2122 may be provided atthe interface between combined head and face cap 2112 and forwardportion 2125 of barrel 2124 to provide a watertight seal. Preferablysealing element 2122 is located an annular groove 123 provided in theouter surface of the barrel 2124. The sealing element 2122 may be anO-ring or other suitable sealing device. In the illustrated embodiment,the sealing element 2122 is a one-way valve formed by a lip seal that isorientated so as to prevent flow from the outside into the interior ofthe flashlight 2100, while simultaneously allowing overpressure withinthe flashlight to escape or vent to the atmosphere.

The design and use of one-way valves in flashlights are more fullydescribed in U.S. Pat. No. 5,003,440 issued to Anthony Maglica, which ishereby incorporated by reference.

Flashlight 2100 of the present embodiment includes a lamp module 2128mounted within the shoulder ring 2126 at the forward end of barrel 2124so that light source 101 is disposed at the aft end of reflector 2118.Lamp module 2128 may have a principal axis 110 of projection which maycoincide with the reflector axis and/or the longitudinal axis offlashlight 2100. In view of the foregoing arrangement, the focus oflight emitted from lamp module 2128 may be adjusted by twisting headassembly 2104 relative to barrel 2124, which may be accomplished viamating threads 172, 174, to cause translation of the head assembly 2104away from or toward lamp module 2128.

The light source 101 of lamp module 2128 includes a first, positiveelectrode and a second, negative electrode. The first positive electrodeis in electrical communication with a compressible positive contact 133(see FIG. 23). The second, negative electrode is in electricalcommunication with the heat sink housing 188, which also acts as thenegative contact of lamp module 2128.

The light source 101 may be any suitable device that generates light.For example, the light source 101 can be an LED lamp, an incandescentlamp, or an arc lamp. In the illustrated embodiment, the light source101 is an LED lamp and lamp module 2128 is an LED module. The LED oflamp module 2128 preferably substantially radiates light at a sphericalangle of less than 180°. In other embodiments, LEDs with other angles ofradiation may be used, including LEDs that radiate at an angle greaterthan 180°.

The structure of an LED module that may be used for lamp module 2128 isdescribed in detail in co-pending U.S. patent application Ser. No.12/188,201, filed Aug. 7, 2008, by Anthony Maglica and U.S. ProvisionalPatent Application Ser. No. 61/145,120, filed Jan. 16, 2009, by StaceyWest at al., the contents of both of which are hereby incorporated byreference.

Referring to FIG. 23, shoulder ring 2126 is configured to be in intimatecontact with the barrel 2124. In the present embodiment, the outerdiameter of a portion of shoulder ring 2126 is provided with externalthreads 141 which are sized to threadably mate with internal threads 139of the forward portion 2125 of barrel 2124. In other embodiments, othermeans for attaching or mounting the shoulder ring 2126 to the interiorsurface of barrel 2124 may be employed, including, for example,press-fitting.

Lamp module 2128 is preferably mounted within shoulder ring 126 via apress-fit operation. Further, the outer surface of heat sink housing 188is preferably shaped to mate with the inner surface of shoulder ring2126 along as much surface area as possible to facilitate electrical andthermal communication between the lamp module 2128 and the shoulder ring2126 and the interference fit between the two. A knurled surface 129,preferably arranged around the circumference of lamp module 2128, mayalso be provided to enhance the interference fit between the lamp module2128 and shoulder ring 2126.

As shown in FIG. 23, the shoulder ring 2126 forms a large heat sink.Moreover, because it has a mass that is substantially greater than thatof lamp module 2128, it quickly draws heat away from lamp module 2128via heat sink 188. Ultimately, the heat drawn away by shoulder ring 2126is efficiently drawn into barrel 2124 because barrel 2124 and shoulderring 2126 are in intimate contact in the forward region 189 of shoulderring 2126. Shoulder ring 2126 may be made out of metal, and morepreferably nickel plated aluminum for enhanced thermal, electrical andcorrosion resistance properties.

The outer diameter of the aft region 191 of shoulder ring 126 isslightly smaller than the inner diameter of the rear portion of barrel2124. Therefore, during assembly, shoulder ring 2126 can readily slidewithin barrel 2124 without damaging any protective coating, such as thatresulting from an anodizing treatment process. On the other hand, theouter diameter of the aft region 191 of shoulder ring 2126 is greaterthan the inner diameter of the forward portion 2125 of barrel 2124.Therefore, the aft region 191 of shoulder ring 2126 serves as a stop tolimit the forward-most position of shoulder ring 2126 as the shoulderring is threaded into internal threads 2139 of barrel 2124.

While shoulder ring 2126, lamp module 2128, and head assembly 2104 donot form part of a mechanical switch for flashlight 2100 in the presentembodiment, in other embodiments they could as described, for example,in connection with U.S. patent application Ser. No. 12/353,396, Jan. 14,2009, by Stacey West, the contents of which are hereby incorporated byreference.

Lamp module 2128 is electrically coupled to flashlight 2100 as follows.Flashlight 2100 may include rechargeable battery pack 2130 that includespositive top contact 214 which is electrically coupled to compressiblepositive contact 133 of lamp module 2128. After the current passesthrough the light source 101, a ground connection extends from thenegative electrode of the light source 101 through heat sink housing188, which acts as the negative contact of lamp module 2128 and shoulderring 2126, which in turn is electrically coupled to the negative contact212 of battery pack 2130.

FIG. 24 is an enlarged partial cross-sectional view of a rear section offlashlight 2100 of FIG. 21 taken through the plane indicated by line102-102. (In FIG. 24, however, battery pack 2130 is not shown incross-section.) The rearward section of flashlight 2100 generallycomprises switch and tail cap assembly 2106. FIG. 25B is an explodedperspective view of switch and tail cap assembly 2106.

Referring to FIGS. 24 and 25B, switch and tail cap assembly 2106 of thepresent embodiment preferably includes sealing element 162, such as aone-way valve, inner tail cap section 2164, commutating rings 190, 192,lower switch housing 2134, spring probe assemblies 2136, 2138, 2140,circuit board 2148, snap dome 152, upper switch housing 2160, locknut166, actuator 154, switch port seal 168, and outer tail cap section2170.

Each spring probe assembly 2136, 2138, 2140 comprises a conductiveplunger 144 slidably disposed within a conductive barrel 2142, and aspring (not shown) positioned between the plunger 2144 and barrel 2142to bias the plunger 2144 away from the barrel 2142.

Lower switch housing 2134 preferably includes three cylindrical channels193 opened to the forward end of lower housing 2134 for receiving andholding at least a portion of the plunger 144 of each spring probeassembly 2136, 2138, 2140. Each of the channels 193 is connected to acylindrical chamber 195 which is axially aligned with the channel 193.The diameter of each cylindrical chamber 195 is larger than each channeldiameter so that each chamber may receive and house the barrel 2142 ofeach spring probe assembly 2136, 2138, 2140. In the present embodiment,cylindrical channels 193 of lower switch housing 2134 are formed in anear 135 projecting radially inward from the outer wall 137 of lowerswitch housing 2134. In the present embodiment, ear 135 is at leastpartially surrounded by a recess 153 for receiving a mating indexingfeature 280 provided on the aft end of battery pack 2130. In otherembodiments, a male indexing feature may be provided on the lowerswitching housing 2134 and a female indexing feature may be provided onthe battery pack 2130.

In the present embodiment, lower switch housing 2134 preferablycomprises a non-conductive material, such as plastic, but other suitablematerials or materials systems may also be used.

In the present embodiment, the barrels 2142 and plungers 2144 of springprobe assemblies 2136, 2138, 2140 preferably comprise a conductivemetal, such as a copper alloy or aluminum.

The channels 193 of lower switch housing 2134, and therefore, springprobe assemblies 2136, 2138, 2140, are configured to align with contactson the bottom side of battery pack 2130. Referring also to FIG. 25C,when battery pack 2130 is installed, spring probe assembly 2136 may bealigned with a bottom central contact 274 of battery pack 2130, springprobe assembly 2138 may be aligned with a bottom middle ring contact 276of battery pack 2130, and spring probe assembly 2140 may be aligned witha bottom outer ring contact 278 of battery pack 2130. In one embodiment,spring probe assemblies 2136, 2138, 2140 are electrically coupled to aGND, a MOM contact, and a +5 VDC contact of battery pack 2130,respectively.

In the present embodiment, circuit board 2148 has slots 148 a (shown inFIG. 25B) for receiving the rearward extending portion 201 of the innertail cap portion 2164. On the other hand, the slots 198 formed by therearward extending portion 201 of the inner tail cap portion 2164 areused to receive a solid portion 148 b of circuit board 148, therebyholding circuit board 148 and the inner tail cap portion 2164 in desiredrelatively position.

Circuit board 2148 preferably includes contacts on both of its sides.Circuit board 2148 may also include conductive vias routed through board2148 to couple contacts on opposite sides. In the present embodiment,the front side of circuit board 2148 (which is facing lower switchhousing 2134) includes three contact pads that are electrically coupledto spring probe assemblies 2136, 2138, 2140, respectively. The rear sideof circuit board 2148 (which is facing the upper switch housing 2160)includes three corresponding contact pads that are located at designatedlocations. Each pair of the corresponding contacts on the front side andrear side of circuit board 2148 are electrically connected throughconductive vias provided in circuit board 2148, or alternatively routingwires.

Upper switch housing 2160 includes a cylindrical channel 197 that allowsactuator 154 to slide within. An annular rim of switch port seal 168 isheld between an annular lip 199 of outer tail cap 2170, which is locatedat the rear end of flashlight 2100. When a user presses on switch portseal 168, actuator 154 is moved forward within channel 197 and engagessnap dome 152 such that MOM and GND contact pads on the rear side ofcircuit board 2148 are electrically coupled through snap dome 152. Whenthe user releases switch port seal 168, the MOM and GND contact pads onthe rear side of circuit board 2148 are no longer electrically coupledthrough snap dome 152. In other embodiments, non-mechanical switches,for example, capacitors, may be used.

Upper switch housing 2160 preferably includes a set of keys 161 a, 161b, 161 c and 161 d (shown in FIG. 25B). These keys 161 a, 161 b, 161 cand 161 d may be used to plug into slots 149 a, 149 b, 149 c and 149 d,respectively, on circuit board 2148 to align upper switch housing 2160and circuit board 2148 in desired relative position.

In the present embodiment, upper switch housing 2160 and actuator 154preferably comprise a non-conductive material such as plastic. Switchport seal 168 preferably comprises a flexible non-conductive material,such as rubber. Snap dome 152 preferably comprises a conductive springmetal. Other suitable material may be used.

Commutating rings 190, 192 are provided at the middle of switch and tailcap assembly 2106. While commutating rings 190, 192 are provided in thepresent embodiment in the form of charging rings to simplify therecharging procedure, in other embodiments, commutating rings 190, 192may take on other forms. In the present embodiment, circuit board 2148is interposed between commutating rings 190, 192. Circuit board 2148 isconfigured to be in electrical communication with commutating rings 190,192, while simultaneously isolating commutating rings 190, 192 fromdirect electrical communication with one another through a shortcircuit. Electrical communication between circuit board 2148 andcommutating rings 190, 192 may be established by providing a conductivetrace at the interface formed between circuit board 2148 and each of thecommutating rings. Commutating rings 190, 192 are preferably aluminumrings.

As best seen from FIGS. 24 and 25B, commutating rings 190, 192 serve asthe interface between an external recharging unit and rechargeablebattery pack 2130 of flashlight 2100. Although not depicted here, thoseskilled in the art will appreciate that the cradle of the rechargingunit should be fashioned in a way to make electrical contact withcommutating rings 190, 192 and hold flashlight 2100 in place whilecharging takes place. Because commutating rings 190, 192 preferablyextend around the entire external circumference of flashlight 2100, arecharging unit having a simple cradle design may be used. For example,a cradle design that permits flashlight 2100 to be placed into therecharging unit in any radial orientation relative to its longitudinalaxis and still be able to make contact with the recharging unit'scharging contacts may be used. Thus, flashlight 2100 does not need to bepressed into the charging unit so that hidden plugs or tabs are insertedinto flashlight 2100 in order to make contact with the charging contactsof the recharging unit.

Inner tail cap section 2164 preferably includes threads 165 on the frontouter surface of inner tail cap section 2164 for mating with threads 131on the rear inner surface of barrel 2124. In addition, inner tail capsection 2164 preferably includes threads 167 on the aft outer surface ofinner tail cap section 2164 for mating with threads 171 on the frontinner surface of the outer tail cap section 2170.

The inner tail cap section 2164 of the present embodiment also includesan annular shoulder 173 formed at the front end of the inner tail capsection 2164. Annular shoulder 173 serves as a stop to prevent lowerswitch housing 2134 from moving forward.

Locknut 166 is preferably threaded into and mated with thread 169 on theaft inner surface of inner tail cap section 2164. Therefore, locknut166, annular shoulder 173 of the inner tail cap section 2164, andthreads 165, 131, 167, 171, 169 function together to integrate theswitch and tail cap assembly 2106.

The construction of inner tail cap section 2164 should be such as tomaintain the commutating rings 190, 192 in electrical isolation from oneanother. In other words, inner tail cap section 2164 should not providea short circuit path between commutating rings 190, 192. Thus, forexample, inner tail cap section 2164 may be constructed from anodizedaluminum or some other electrically non-conductive material. Locknut 166may be made from metal or plastic and is not required to be conductiveas it does not form part of any electrical path in the presentembodiment.

The rear end of the outer tail cap section 2170 preferably has aplurality of icons 2180 (best shown in FIG. 21B) to be used asindications for functional mode selection. The icons 2180 and theircorresponding functional modes together with the operation procedureswill be described in connection with the description of flashlight 2300later.

A one-way valve, such as a lip seal 162, may be provided at theinterface between barrel 2124 and inner tail cap section 2164 to providea watertight seal while simultaneously allowing overpressure withinflashlight 2100 to vent to the atmosphere. The design and use of one-wayvalves in flashlights are more fully described in U.S. Pat. Nos.5,003,440 issued to Anthony Maglica, which is hereby incorporated byreference. However, other forms of sealing elements, such as an o-ring,may be used instead of lip seal 162 to form a watertight seal. Lip seal162 preferably comprises a non-conductive material such as rubber.

Other configurations of switch and tail cap assembly 2106 may be used.For example, the switch function may be included in a side, push buttonswitch or in an internal rotating head assembly switch such as thatemployed in U.S. patent application Ser. No. 12/353,396, filed Jan. 14,2009.

Referring now to FIGS. 25A and 25C, the rechargeable battery pack 2130is now further described. In general, battery pack 2130 preferablyincludes a rechargeable battery, a circuit board containing electronicssuch as recharging circuit and/or circuits for other functions andcontacts to electrically connect battery pack 2130 to the rest of theflashlight 2100 or other lighting device. As such, battery pack 2130 maygenerally represent a self-contained unit that may be inserted intobattery compartment 127 of barrel 2124 along with other components shownin FIG. 25A. It is also preferred that battery pack 2130 providesprotection for the electronics and other components therein. In otherembodiments, battery pack 2130 does not have a circuit board mountedwith components such as accelerometer 1058, therefore, functions can beprovided by circuit board 2148 in the switch and tail cap assembly 2106.

Referring to FIG. 25C, the rear end of battery pack 2130 includes abottom central contact 274, a bottom middle ring contact 276, and abottom outer ring contact 278. An indexing feature 280 formed from arearward extending wall may be located on the aft end of battery pack2130, such as between the bottom middle ring contact 276 and the bottomouter ring contact 278. A slot 284 provided in the indexing feature 280is sized to receive the ear 135 of the lower switch housing 134 so thatindexing feature 280 may be received within recessed area 153surrounding ear 135 of the lower switch housing 2134, thereby, forming aplug and socket type connection. As a result, when the switch and tailcap assembly 2106 is rotated to screw it into barrel 2124, battery pack2130 will also be rotated once indexing feature 280 is received withinrecess 153. Therefore, the desired orientation of the switch and tailcap assembly 2106 and an assembly circuit board (not shown) in batterypack 2130 will remain aligned at all times. This feature is helpful whenaccelerometer 1058 discussed below is located in the assembly circuitboard of battery pack 2130 so that the orientation of icons 2180 can beautomatically detected based on the output of accelerometer 1058.

Battery pack 2130 provided by the exemplary flashlight 2100 is describedin detail in co-pending U.S. Provisional Patent Application Ser. No.61/145,120, filed Jan. 16, 2009, by Stacey West et al., the contents ofwhich were incorporated by reference above.

The electrical circuits of flashlight 2100 and the functions they serveare now further described. The electrical circuits of flashlight 2100include a load circuit to power the light source 101, a controllercircuit for powering the controller and other electronics on circuitboard 2148 and, if available, in battery pack 2130, and a chargingcircuit for recharging rechargeable battery in battery pack 2130.

When battery pack 2130 is installed into battery compartment 127 ofbarrel 2124 a completed electrical path for the light source 101 (orelectrical load) may be formed from the top positive contact 214 ofbattery pack 2130 to the positive contact 133 of lamp module 2128 andthrough the light source. This electrical path then extends from heatsink housing 188 of lamp module 2128 to the shoulder ring 2126 and thento the top outer ring contact 212 of battery pack 2130.

The control circuit starts from a bottom outer ring positive contact ofbattery pack 2130 to spring probe assembly 2140 to circuit board 2148,and return from a ground pad of circuit board 2148 to spring probeassembly 2136 to central ground contact of battery pack 2130.

The high side of the charging circuit to battery pack 2130 extends frompositive charging ring 190, to circuit board 2148, spring probe assembly2140, into battery pack 2130 via an outer bottom ring contact 270 ofbattery pack 2130. The charging circuit may then return from a bottomnegative contact 274 of battery pack 2130 to spring probe assembly 2136,circuit board 2148, to ground charge ring 192.

Another preferred flashlight embodiment 2300 is now described withreference to FIG. 26. As shown, flashlight 2300 generally includesbarrel 2324, head assembly 2104 located at the forward end of barrel2324, and switch and tail cap assembly 2306 located at the rear end ofbarrel 2324. The head assembly 2104 is disposed about the forward end ofthe barrel 2324, and the switch and tail cap assembly 2306 encloses theaft end of barrel 2324.

Barrel 324 may include a textured surface 2308 along a portion of itslength for a user to grip. Textured surface 2308 may be provided bybroaching. Alternatively, textured surface 2308 may comprise a knurledor machine surface. Any desired pattern may be used for textured surface2308.

FIG. 27 is a partial cross-sectional view of flashlight 2300 of FIG. 26taken along the plane indicated by line 302-302. FIG. 28 is an enlargedpartial cross-sectional view of a forward section of flashlight 2300 ofFIG. 26 taken through the plane indicated by line 302-302. (The portionsof FIGS. 27-29 that relate to the battery cassette 2330 are not shown incross-section.)

Barrel 2324 is a hollow, tubular structure suitable for housing aportable source of power, such as, for example, battery cassette 2330.Thus, barrel 2324 serves as a housing for receiving a portable source ofpower having a positive and a negative electrode or terminal.

In the illustrated embodiment, barrel 2324 is sized to accommodatebattery cassette 2330. In other embodiments, however, the batterycassette 2330 may be omitted and the barrel 2324 sized to accommodateone or more alkaline dry cell or rechargeable batteries of desired sizeand capacity. Further, if a plurality of batteries is employed,depending on the implementation, the batteries may be connectedelectrically in parallel or series. Other suitable portable powersources, including, for example, high capacity storage capacitors mayalso be used.

In the illustrated embodiment, barrel 2324 includes a forward portion2125 that extends beneath combined head and face cap 2112 so that theouter surface of the head assembly 2104 is generally flush with that ofthe barrel 2324. The inner diameter of the forward portion 2125 issmaller than the inner diameter of the rest of barrel 2324. Also, theouter diameter of at least a portion of the forward portion 2125 may besmaller than the outer diameter of the rest of barrel 2324, so that whenflashlight 2300 is assembled, the outer portion of combined head andface cap 2112 and the outer portion of barrel 2324 may form asubstantially uniform, cylindrical surface. Alternatively, the combinedhead and face cap 2112 and barrel 2324 may have different shapes.

Barrel 2324 is preferably made out of aluminum, but other suitable metalor non-metal (e.g. plastic) materials may also be used. Although barrel2324 is preferably made out of aluminum, in the embodiment of flashlight2300 described below, barrel 2324 is not used as an electrical path forconnecting either the light source 101 or circuit board 2348 to thebattery cassette 2330. As a result, barrel 2324 does not form part ofthe main power circuit for either the light source 101 or circuit board2348. In other embodiments, however, the barrel 2324 may comprise partof the main power circuit for light source 101 and/or circuit board2348, such as where one or more batteries are used in place of batterycassette 2330. In such embodiments, barrel 2324 and other componentspreferably comprise a conductive material, or include a conductive path.

In the illustrated embodiment, barrel 2324 includes external threads 174formed on the outer diameter of the forward portion 2125, internalthreads 2139 formed on the inner diameter of the forward portion 2125,and internal threads 331 formed on the inside diameter of its aft end(best seen in FIG. 29). The barrel 2324 of the present embodiment alsoincludes an annular shoulder 182 formed at the aft end of the forwardportion 2125. Annular shoulder 182 acts as a stop for shoulder ring 2126disposed in the forward end of barrel 2124.

FIG. 30A is an exploded perspective view of head assembly 2104, barrel2324, lamp module 2128, and battery cassette 2330 of flashlight 2300 ofFIG. 26. Referring to FIGS. 28 and 30A, head assembly 2104 may generallyinclude combined head and face cap 2112, lens 116 and reflector 2118.Head assembly 2104 and components including combined head and face cap2112, lens 116, reflector 2118, shoulder ring 2126, lamp module 2128,o-rings 114, and lip seal 2122 have been fully described in connectionwith FIGS. 23 and 25A.

Other configurations of the head assembly 2104 may also be used. Forexample, in other embodiments, head assembly 2104 may form a part of amechanical switch means to provide a user interface.

Referring to FIG. 28, lamp module 2128 is electrically coupled toflashlight 2300 as follows. Flashlight 2300 of the present embodimentincludes a battery cassette 2330 that includes positive electrode 454which is electrically coupled to compressible positive contact 133 oflamp module 2128. After the current passes through the light source, aground connection extends from the negative electrode of the lightsource through heat sink housing 188, which acts as the negative contactof lamp module 2128, and shoulder ring 2126, which in turn iselectrically coupled to a connector pin 424 of battery cassette 2330.The ground path continues to the conductive ring 335 of lower switchhousing 2334 (best shown in FIG. 29), to spring probe assembly 2140, andto circuit board 2348 which includes a negative contact that is coupledto a negative electrode on battery cassette 2330 thereby completing thecircuit.

FIG. 29 is an enlarged partial cross-sectional view of a rearwardsection of flashlight 2300 of FIG. 26 taken through the plane indicatedby line 302-302. (In FIG. 29, however, battery cassette 2330 is notshown in cross-section.) The rearward section of flashlight 2300generally comprises switch and tail cap assembly 2306 as reflected inFIGS. 26 and 27. FIG. 30B is an exploded perspective view of switch andtail cap assembly 2306.

Referring to FIGS. 29 and 30B, switch and tail cap assembly 2306 of thepresent embodiment preferably includes lower switch housing 2334, springprobe assemblies 2136, 2138, 2140, circuit board 2348, snap dome 152,actuator 354, upper switch housing 2360, sealing element 162, such as aone-way valve switch port seal 168, and tail cap 2370. Spring probeassemblies 2136, 2138, 2140 have been fully described in connection withFIGS. 24 and 25B.

Lower switch housing 2334 preferably includes three cylindrical channels393 opened to the forward end of lower switch housing 2334 for receivingand holding at least a portion of the plunger 2144 of each spring probeassemblies 2136, 2138, 2140. Each of the channels 393 is connected to acylindrical chamber 395 which is axially aligned with the channel 393.The diameter of each cylindrical chamber 395 is larger than the channeldiameter so that each chamber may receive and house the barrel 2142 ofeach spring probe assemblies 2136, 2138, 2140. In the presentembodiment, lower switch housing 2334 preferably comprises anon-conductive material, such as plastic, but other suitable materialsor materials systems may also be used.

Spring probe assemblies 2136, 2138, 2140 also push forward until theirfront end engage with a contact described below. The channels 393 oflower switch housing 2334 and therefore, spring probe assemblies 2136,2138, 2140 are configured to align with contacts on the bottom ofbattery cassette 2330. When battery cassette 2330 is installed, springprobe assembly 2136 may be aligned with a bottom central contact 451 ofbattery cassette 2330, and spring probe assembly 2138 may be alignedwith a bottom outer contact 434 of battery cassette 2330. On the otherhand, spring probe assembly 2140 may be aligned with a conductive ring335 of lower switch housing 2334. The conductive ring 335 may be furtheraligned with a rear end 429 of connector pin 424 of battery cassette2330.

In the present embodiment, lower switch housing 2334 preferablycomprises a non-conductive material, such as plastic, but other suitablematerials may be used. Spring probe assemblies 2136, 2138, 2140 arepreferably made out of metal so as to form part of the electrical pathsof flashlight 2300 to be described later.

Contact ring 335 (shown in FIGS. 29 and 30B), which is preferably madeout of metal, may be co-molded with lower switch housing 2334 to providean interface between the spring probe assembly 2140 and the rear end 429of connector pin 424 of battery cassette 2330. Thus, a portion of thenegative, or ground, path for the lamp module 2128 is formed.

Circuit board 2348 preferably includes contacts on both sides. Circuitboard 2348 may also include conductive vias routed through board 2348 tocouple the contacts on opposite sides. Alternatively, wires may berouted around board 2348 to couple contacts on opposite sides. Circuitboard 2348 may also include electronic components installed thereon. Inthe present embodiment, the front side of circuit board 2348 (which isfacing the lower switch housing 2334) includes three contact pads thatare electrically couple to spring probe assemblies 2136, 2138, 2140,respectively. The rear side of circuit board 2348 (which is facing theupper switch housing 360) includes contact pads that correspond toSWITCH 1020 and 4.5 VDC 1014 and that are located at designatedlocations. Each pair of the corresponding contacts on the front side andrear side of circuit board 2348 are electrically connected throughconductive vias provided in circuit board 2348, or alternatively routingwires. The electronic components and their function assembled on circuitboard 2348 will be described later in this specification.

Upper switch housing 2360 includes a cylindrical channel 397 that allowsactuator 354 to slide within. An annular rim of switch port seal 168 isheld between an annular lip 399 of outer tail cap 2370, which is locatedat the rear end of flashlight 2300. When a user presses on switch portseal 168, actuator 354 is moved forward within channel 397 and engagessnap dome 152 such that SWITCH contact pad 1020 and 4.5 VDC contact pad1014 on the rear side of circuit board 2348 are electrically coupledthrough snap dome 152. When the user releases switch port seal 168, theSWITCH contact pad 1020 and 4.5 VDC contact pad 1014 on the rear side ofcircuit board 2348 are no longer electrically coupled through snap dome152. In other embodiments, non-mechanical switches, for example,capacitors, may be used.

Upper switch housing 2360 preferably includes a set of keys 361 a, 361 band 361 c (shown in FIG. 30B). These keys 361 a, 361 b and 361 c areintended to be plugged into slots 349 a, 349 b and 349 c, respectively,on circuit board 2348 to align the upper switch housing 2360 and circuitboard 2348 in a desired relative position. The configuration of a shortkey 361 a on one side while a short key 361 b and a long key 361 c onthe other side creates a polarized keying feature.

In the present embodiment, as best seen in FIG. 30B, upper switchhousing 2360 preferably includes an alignment feature 360 a projectingforward and received within a mating recess 334 a on lower switchhousing 2334. These mating features 360 a, 334 a may be used duringassembly to help align keys 361 a, 361 b, 361 c with their slots 349 a,349 b, 349 c formed in circuit board 2348 and mating holes (not shown)formed in the bottom of lower switch housing 2334. The mating holesformed in the bottom of the lower switch housing 2334 are preferablydimensioned to receive their respective key so as to form aninterference fit. In other embodiments, a male alignment feature may beprovided on the lower switch housing 2334 and a corresponding femalefeature may be provided on the upper switch housing 2360.

In the present embodiment, upper switch housing 2360 and actuator 354preferably comprise a non-conductive material, such as plastic. Switchport seal 168 also preferably comprises a flexible non-conductivematerial, such as rubber. Snap dome 152 preferably comprises aconductive material such as metal. Other suitable materials may be used.

A one-way valve, such as a lip seal 162, may be provided at theinterface between barrel 2324 and the switch and tail cap assembly 2306to provide a watertight seal while simultaneously allowing overpressurewithin the flashlight to expel or vent to atmosphere. However, otherforms of sealing elements, such as an o-ring, may be used instead of lipseal 162 to form a watertight seal. Lip seal 162 is preferably made outof non-conductive material, such as rubber.

Tail cap 2370 preferably includes threads 331 (shown in FIGS. 29 and31A) on the front outer surface of tail cap 2370 for mating with threads329 on the rear inner surface of barrel 2324.

Other configurations of switch and tail cap assembly 2306 may be used.For example, the switch function may be included in a side, push buttonswitch or in an internal rotating head assembly switch such as thatemployed in U.S. patent application Ser. No. 12/353,396, filed Jan. 14,2009.

Referring now to FIGS. 28, 29 and 30A, battery cassette 2330 preferablycontains batteries used to power the flashlight 2300 or other lightingdevice. After the batteries are inserted into battery cassette 2330, itmay be inserted into flashlight barrel 2324 along with other componentsof flashlight 2300. In the present embodiment, a center connector 450 isused to provide positive contact at both ends of battery cassette 2330,i.e., the positive contact at its top end 454 and the positive contactat its bottom central contact 451. In the present embodiment, a springprobe 424 is used to provide negative contact at both ends of batterycassette 2330, i.e., the negative contact at its top end 423 and thenegative contact at its bottom 429.

Battery cassette 2330 included in the exemplary flashlight 2300 isdescribed in detail in co-pending U.S. Provisional Patent ApplicationSer. No. 61/145,120, filed Jan. 16, 2009, by Stacey West et al., thecontents of which were incorporated by reference above.

Referring also to FIG. 32, when battery cassette 2330 is installed intobattery compartment 327, in the present embodiment, an electrical pathfor the light source (or electrical load) may be formed from the centralelectrode or forward end 454 of battery cassette 2330 to thecompressible positive contact 133 of lamp module 2128, and through thelight source 101. The electric path continues from the light source 101to heat sink 188 of lamp module 2128, to conductor pin 424 of batterycassette 2330, contact ring 335 of lower switch housing 2334, springprobe assembly 2140, a load switch 1006 on circuit board 2348, groundpad on the front side of circuit board 2348, spring probe assembly 2138,and finally to the negative electrode 434 of battery cassette 2330.

The functions and electrical circuit supporting the functions forflashlight 2300 will be described hereafter. The functions andelectrical circuit supporting the functions for flashlight 2300 may alsobe used for flashlight 2100.

In the present embodiment, flashlight 2300 includes five predefinedfunctional modes: a dim light with a variable brightness (DIM), ablinking light with a variable blinking frequency (STROBE), a SOS modewith variable brightness (SOS), a motion sensitive signal mode (SIGNAL),and a night light mode (NITE LITE). It is understandable that the modespresented in the present embodiment can be removed and/or other modescan be added to make a flashlight with desirable functions. In thisdescription, blink and strobe are interchangeably used. Also, nightlight and NITE LITE are interchangeably used.

The rear end of the tail cap 2370 preferably has a plurality of icons2180 to be used as indications for functional mode selection. As theexample shown in FIG. 31B, tail cap 2370 has five mode associated icons2370 a, 2370 b, 2370 c, 2370 d and 2370 e evenly spaced around the rearcircumference 2371 of tail cap 2370. The icon associated with the DIMmode 2370 a is positioned at the 12:00 o'clock direction, the iconassociated with the STROBE mode 2370 b is positioned between the 12:00o'clock and 3:00 o'clock direction, the icon associated with the SOSmode 2370 c is positioned between the 3:00 o'clock and 6:00 o'clockdirection, the icon associated with the SIGNAL mode 2370 d is positionedbetween the 6:00 o'clock and 9:00 o'clock direction, and the iconassociated with the NITE LITE mode 2370 e is positioned between the 9:00o'clock and 12:00 o'clock direction. The separation between each pair ofadjacent icons is, therefore, 360° divided by 5 which is 72°. In otherembodiments, icons 2370 a, 2370 b, 2370 c, 2370 d and 2370 e do not needto be evenly spaced around the rear circumference 2371 of tail cap 2370.In other embodiments, the order of icons 2370 a-e may be rearranged inFIG. 31C, or in some other order.

Flashlight 2300 may be turned on by pressing the momentary switch for apredetermined period of time while the flashlight is in horizontalposition to cause it to enter a new mode of operation. The new mode ofoperation is determined by the position of the flashlight. In otherwords, the new mode of operation is determined by the icons which isfacing at a predefined position. In the present embodiment, the modeassociated with a specific icon 2180 facing at the 12:00 o'clockdirection is selected as the new mode the flashlight 2300 enters. Thisinterface with mode associated icons 2180 simplifies the mode selectionprocedure for the user. Any mode can be immediately selected withouthaving to perform a sequence of operations.

In the present embodiment, icons 2180 are laser preferably engraved toprovide high contrast for easily seen, even in poor lighting conditions.Other means for displaying icons 2180 can also be used. For example,icons 2180 can be painted, labeled, laminated, silkscreening, stamping,pad printing, mechanically engraving, or heat transfer/dye sublimation.

In addition, icons 2180 can be illuminated, for example, by phosphorink, or other technique such as backlighting, to make icons 2180 glow inthe dark. As a result, icons 180 can be visible in darkness. And asshown in FIG. 31D, seal 168 of tailcap 2370 may include a bump or rib2399 that may be aligned with one of the icons 2180, e.g., the DIM icon2370 a to help the user locate particular icons 2370 in the dark.

Icons 2180 can be applied to flashlight 2300 after switch and tailcapassembly 2306 is assembled. If this is the case, the tips of springprobe assemblies 2136, 2138, 2140 can be used as indexing fororientation while icons 2180 are applied.

In other embodiments, icons 2130 can be placed other than the rearcircumference 2371 of tail cap 2370. For example, icons 2180 can beplaced on the middle outer circumference of tail cap 2370.

In other embodiments, more or less than five icons can be used dependingon the number of functional modes desired.

Because icons 2180 are preferably engraved on the rear circumference2371 of tail cap 2370, in the present embodiment, a keying featurebetween the upper switch housing 2360 and circuit board 2348 is used tohold the orientation of the circuit board 2348 to the laser engravedicons 2180.

Alternatively, if a keying feature is not used, a calibration routinecan be performed to align the icons to circuit board 2348. If this isthe case, the calibration can be performed during manufacturing. Ifunintended rotation occurs after manufacturing, a procedure can beperformed by circuit board 2348 to re-align the icons with the circuitboard 2348.

FIG. 32 is a block diagram illustrating an electric circuit forflashlight 2300. The electric circuit includes a power source 2330, alight source 2128, and a circuit board 2348. The circuit board 2348 mayinclude voltage regulator circuit and interface 1004, load switchcircuit 1006, controller circuit 1008, and accelerometer circuit 1010.

Circuit board 2348 may also include audio interface & speaker 518 andvibrator 520. This may be desirable, for example, where an audible ortactile response is desired in response to the entry of a command, suchas selection of one or more modes as described below. Instead oflocating the audio interface & speaker 518 and vibrator 520 on circuitboard 2348, one or both of them may be located off board. In otherwords, audio interface & speaker 518 and/or vibrator 520 is not requiredto be mounted on circuit board 2348 but may be included elsewhere withinflashlight 300.

The circuit board 2348 may include I/O pads to engage external devices.I/O pads may include top +4.5 VDC 1012, bottom +4.5 VDC 1014, GND 1016,LED_OUT 1018 and SWITCH 1020.

Referring also to FIG. 30C, the I/O pads top +4.5 VDC 1012 and GND 1016may be coupled to the central contact 451 and the outer contact 434 ofbattery cassette 2330, respectively. I/O pads bottom +4.5 VDC 1014 andSWITCH 1020 may be coupled to snap dome 152. When a user presses onswitch port seal 168, actuator 354 may be pushed forward to engage snapdome 152 to close the switch between SWITCH 1020 and +4.5 VDC 1014. Whenthe user releases switch port seal 168, the switch is open and SWITCH1020 is no longer coupled to +4.5 VDC 1014.

Detailed electrical circuit schematics of an embodiment of circuit board2348 are shown in FIGS. 33A-D.

FIG. 33A shows a circuit schematic diagram of a preferred voltageregulator circuit 1004. Voltage regulator circuit 1004 may include a lowdropout regulator 1002, which may be implemented by a DC linear voltageregulator operated with a small input-output differential voltage.Signal line 1022 is an output from two diodes 1024, 1026 which may bedriven by signal lines SWITCH 1020 and SW_ON 1046, respectively. Thisconfiguration preferably allows the higher voltage from signal linesSWITCH 1020 or SW_ON 1046 to enable low dropout regulator 1002.

In a preferred embodiment, the output of low dropout regulator 1002 maybe set to +3.3V 1028 for use as a power supply source to othercomponents, for example, controller circuit 1008. In one embodiment, acommercial stand-alone LDO regulator, e.g., ISL9003AIRUNZ manufacturedby Intersil Coperation, may be used. It should be understood that othertypes of linear regulator circuits may also be employed.

The voltage supply level from battery (i.e. +4.5 VDC 1012) may bemonitored by controller circuit 1008 through signal line ADC_VBAT 1032.Signal line ADC_VBAT 1032 may be generated by a voltage divider from+4.5 VDC 1012.

The I/O pad SWITCH 1020 may be used to generate signal MOM 1048 forsending to controller circuit 1008 as an indication that a user ispressing on switch port seal 168 when MOM 1048 is low. MOM 1048 may begenerated by NPN bipolar transistor 1052.

FIG. 33B is a circuit schematic diagram of a preferred controllercircuit 1008. Controller circuit 1008 may include controller 1030 withinput and output connections. Controller 1030 may receive input signalsthrough signal lines ADC_VBAT 1032, Z-VOUT 1034, Y-VOUT 1036, X-VOUT1038, SCK 1040, MISO 1042, MOM 1048 and RESET 1050. Controller 1030 mayalso deliver output signals through signal lines LOAD_ENABLE 1044 andSW_ON 1046. The power supply of controller 1030 may be supported by the+3.3V 1028 power supply.

In one embodiment, controller 1030 is a commercially availablecontroller having embedded memory, e.g., an ATtiny24 which is an 8-bitcontroller manufactured by Atmel Corporation. In another embodiment,controller 1030 may be a microprocessor. Yet in other embodiments,controller 1030 may be discrete circuits. Those skilled in the art willappreciate that other types of controller circuits may also be employed.

FIG. 33C shows a circuit schematic diagram of preferred load switchcircuit 1006. In the embodiment of FIG. 33C, the load switch may beimplemented by NMOS 1054. The source of PMOS 1054 may be coupled to topGND 1016 while the drain of NMOS 1054 may be coupled to LED_OUT 1018.The gate of NMOS 1054 may be coupled to LOAD_ENABLE 1044. Electric powermay flow from LED_OUT 1018 to GND 1016 to form a portion of a loop ofelectrical current that may turn on lamp module 2128.

Those skilled in the art will appreciate that other types of driver andload switch circuits can also be employed.

FIG. 33D shows a circuit schematic diagram of a preferred accelerometercircuit 1010. Accelerometer circuit 1010 may include outputs Z-VOUT1034, Y-VOUT 1036 and X-VOUT 1038 that may also be coupled to thecontroller circuit 1008 for further processing.

Accelerometer circuit 1010 preferably includes an inertial sensor 1058that may receive information from its internal sensing elements and thatmay provide analog signals according to the measurements from theinternal sensing elements. Inertial sensor 1058 may be used to measurethe Earth's static gravity field by providing acceleration informationin three axes, e.g., mutually orthogonal axes, namely X, Y and Z. Thepower supply VDD of 3-axis accelerometer circuit 1010 may be supportedby the +3.3V 1028 power supply.

If the Z axis of inertial sensor 1058 is pointing towards the center ofthe Earth, then X and Y will have an acceleration of zero. Z, however,will experience an acceleration of −1 G due to the gravity of the Earth.If inertial sensor 1058 as flipped 180° so that Z is pointing away fromthe Earth, X and Y will remain at zero, but Z will have an accelerationof +1 G.

Inertial sensor 1058 may be attached to circuit board 2348 so that theX, Y and Z axes are fixed relative to flashlight 2300. In a preferredembodiment, inertial sensor 1058 is oriented on board 2348 so that the Zaxis extends along the longitudinal axis of flashlight 2300. As such,when flashlight 2300 is positioned horizontally, the Z axis also extendshorizontally. In this position, when flashlight 2300 rotated left orright about the longitudinal axis of the flashlight 2300 to a differentorientation, as the magnitudes of the acceleration in the X and Y axeschange during rotation, gravity information on X and Y may be sent tocontroller 1030 through X-VOUT 1038 and Y-VOUT 1036, respectively todetermine the orientation of flashlight 2300. In other words, theorientation of flashlight 2300 can be determined.

Relative angular rotation of flashlight 2300 may also be detected. Whenflashlight 2300 is positioned horizontally, the Z axis also extendshorizontally. In this position, when X and Y are rotated left or rightabout the longitudinal axis of the flashlight 2300, as the magnitudes ofthe acceleration in the X and Y axes change during rotation, gravityinformation on X and Y may be sent to controller 1030 through X-VOUT1038 and Y-VOUT 1036, respectively. Relative angular rotation may becomputed by controller 1030. Controller 1030 may use the information onX-VOUT 1038 and Y-VOUT 1036 to determine whether there is a rotationabout the longitudinal axis of flashlight 2300.

In a preferred embodiment, the switch for flashlight may be located inswitch and tail cap assembly 2106. In this arrangement, the startingorientation of the X and Y axes are unknown, so a starting may becalculated based on the Earth's gravitational field in the X and Y axesin the starting orientation. Once their starting orientation isestablished, subsequent angular measurements may be made to track therotation of flashlight 2300.

It is preferred that flashlight 2300 be positioned approximatelyhorizontally for the user to obtain higher resolution when rotating,i.e., better sensing of the rotation of the X and Y axes. As the Z axistilts farther from horizontal, rotational errors may occur. Inoperation, it is preferred that flashlight 2300 be held to an angle fromhorizontal. If the tilting is greater than 30°, it is preferred that theZ axis be monitored and the rotational input ignored until flashlight2300 is tilted back within the +/−30° window. The above angles, however,may be decreased or increased in different implementations.

In a preferred embodiment, inertial sensor 1058 may be a commerciallyavailable microelectro-mechanical systems (MEMS), e.g., LIS394AL whichis a 3-axis accelerometer manufactured by ST Microelectronics. Thoseskilled in the art will appreciate that other types of inertial sensorcircuits may also be employed.

The variable brightness on lamp module 2128 may be determined bychanging the duty cycle on lamp module 2128 with a frequency that ishigher than a human's eye can detect. A duty cycle on lamp module 2128may be produced by a sequence of high and low states on the output ofload switch circuit 1006, which can be driven by controller 1008together with other components. If the time period of conduction islonger, lamp module 2128 is brighter. On the other hand, if the timeperiod of conduction is shorter, lamp module 2128 is dimmer.

The variable blinking rate on lamp module 2128 can also be determined bychanging the duty cycle on lamp module 2128 but with a frequency that isdetectable by a human's eye. The circuits that support the variableblinking rate can be the same as that which support variable brightnessdescribed previously.

As a combination, the SOS mode with variable brightness or a blinkinglight with variable brightness on lamp module 2128 may be produced bymaking a duty cycle on lamp module 2128 with a frequency that isdetectable by a human's eye. During the low cycle, lamp module 2128 isoff, while during the high cycle, lamp module 2128 can have a duty cyclewith a frequency that is higher than a human's eye can detect. In otherwords, there is a high frequency duty cycle within the high period of alow frequency duty cycle. This function can be performed by controller1008.

As indicated above, it is preferred that flashlight 2300 may operate inmultiple modes. The operation and accessing of these modes are nowfurther discussed. FIG. 34 is a flow diagram illustrating a preferredmanner of operation 2702 in which flashlight 2300 may access and performvarious modes.

When flashlight 2300 is turned off 2704, circuit board 2348 can still bepowered by the battery cassette 2330. Therefore, flashlight 2300continuously monitors the position and motion of the flashlight 2300while detecting the position of momentary switch 2168. If switch 2168 isdepressed 2706, flashlight 2300 is turned on in normal mode 2708.

When flashlight 2300 is turned on in normal mode 2708, default intensityinformation may be loaded from a memory 2710 for controller 1008 toprovide a control signal to control the brightness on lamp module 2128.In a preferred embodiment, the memory may be an EEPROM embedded incontroller 1008. The default intensity information can be the intensityof the last usage before flashlight 2300 is turned off. Alternatively,the default intensity information may be a predetermined setting, forexample, the maximum intensity. Other intensities may be predetermined.

After the default intensity information is loaded from memory 2710, ifflashlight 2300 is not held in horizontal position when turned on or ifswitch 168 is not continuously depressed for more than a predeterminedperiod of time 2712, flashlight 2300 continues in normal mode 2714. Inone embodiment, the predetermined period of time is one second. Othertime periods can be used. At this stage, flashlight 2300 is working as anormal flashlight with a steady brightness and can be turned off whenthe switch 168 is depressed a second time.

On the other hand, if flashlight 2300 is held in a horizontal positionwhen turned on while switch 168 is continuously depressed for more thana predetermined period of time 2712, flashlight 2300 can enter into anew mode of operation.

The new mode of operation can be designated as one of the followingexamples: a dim light with a variable brightness (DIM), a blinking lightwith a variable blinking frequency (STROBE), an SOS mode with variablebrightness (SOS), a motion sensitive signal mode (SIGNAL), or a nightlight mode (NITE LITE). The new mode of operation is determined by theicon associated with the new mode. If a specific icon is facing up, orin the 12:00 o'clock direction, while switch 168 is continuouslydepressed for more than a predetermined period of time 2712 andflashlight 2300 is held in horizontal position when turned on, the modeassociated with the specific icon is selected 2716.

For example, if the DIM icon 2370 a is facing up as shown in FIG. 31B,then after step 2716, the DIM functional mode is selected. On the otherhand, for example, if the SOS icon 2370 c is facing up, then after step2716, the SOS functional mode is selected. This interface simplifies themode selection procedure for a user. Any mode can be directly selectedby facing the desired mode associated icon to a predefined position sothat guessing or remembering a sequence of operations is not required bya user.

When flashlight 2300 enter a new functional mode 2718, a defaultintensity information may be loaded from a memory 2710 for controller1008 to provide a control signal to control the brightness on lampmodule 2128. The default intensity information can be the intensity ofthe last usage before flashlight 2300 is turned off. Alternatively, thedefault intensity information may be a predetermined setting, forexample, the maximum intensity. Other intensities may be predetermined.

In the present embodiment, when the current mode is DIM mode, STROBEmode, SOS mode or SIGNAL mode, the intensity of the last usage beforeflashlight 2300 is turned off is used as the default intensity. On theother hand, if the current mode is NITE LITE mode, the maximum intensityis used as the default intensity.

At this moment, if switch 168 is released 2720, flashlight 2300 willcontinue in the current functional mode with default intensity setting2722 until flashlight 2300 is turned off by a designated method. Forexample, if switch 168 is depressed and then released, flashlight 2300may recognize this sequence as a switch off command and flashlight 2300will be turned off.

If flashlight 2300 is rotated left or right 2724 about its principalaxis of projection 2310 while switch 168 is still continuously depressed2720, the amount of rotation can be calculated by controller 1008 and anadjustment is performed 2726. If the current mode of operation is DIMmode, for example, the brightness of flashlight 2300 may be varied basedon the calculated amount of rotation 2726. On the other hand, if thecurrent mode of operation is STROBE mode, then, the frequency of dutycycle may be varied based on the calculated amount of rotation 2726.

In a preferred embodiment, before the flashlight 2300 is rotated, theflashlight brightness is set to the intensity information stored inmemory. When the flashlight 2300 is rotated left or right 10°, theflashlight brightness is set to the maximum if the current mode ofoperation is the DIM mode, the SOS mode, or the SIGNAL mode. While whenthe flashlight 2300 is rotated left or right 45° and beyond, theflashlight brightness is set to the minimum. In other words, when theflashlight 2300 is rotated left or right from 10° to 45°, the flashlightbrightness can change linearly from maximum to minimum.

If the current mode of operation is the STROBE mode, when flashlight2300 is rotated left or right 10°, the flashlight frequency is set tothe maximum. While when the flashlight 2300 is rotated left or right 45°and beyond, the flashlight frequency is set to the minimum. In otherwords, the flashlight 2300 is rotated left or right from 10° to 45°, theflashlight frequency can change linearly from maximum to minimum.

Since mode selection is based on icon position at startup, rotating thebarrel along the principle axis of projection of flashlight 2300 is usedonly for mode adjustments. Therefore, the adjustments can be performedby either left rotation or right rotation. The adjustments to the modesare symmetrical and mirrored across a virtual vertical plane that runslongitudinally through the principal axis of projection 2310 offlashlight 2300, therefore, this feature helps the users with eitherleft-handed or righted-hand preference.

In the present embodiment, the maximum brightness is performed byproviding a pulse current with 100% duty cycle to the lamp module 2128and the minimum brightness has a duty cycle of 5%.

If a suitable brightness (for DIM, SOS, or SIGNAL modes) or frequency(for STROBE mode) is found while flashlight 2300 is rotating left orright 2724, the switch 158 may be released 2728 and the brightness orfrequency existing at that time may be stored in a memory and performthe selected mode function 2730. Flashlight 2300 may retain that levelof brightness or frequency until a new setting is stored next time.

On the other hand, if switch 168 is released 2728 and the current modeis SIGNAL mode, the motion sensitive signal operation may be performed2730 by detecting whether there is a left or right rotation along theprincipal axis of projection 2310 of flashlight 2300. If a rotation isdetected, then flashlight 2300 can be turned on. If the flashlight 2300is turned back to the previous position, then flashlight 2300 can beturned off. In other words, flashlight 2300 can be toggled between onand off by rotating it left or right and then rotating it back.

Flashlight 2300 may be turned off 2734 by a designated method. Forexample, if switch 168 is depressed and then released, flashlight 2300may recognize this sequence as a switch off command 2732 and flashlight2300 will be turned off 2734.

Those skilled in the art will appreciate that the flow diagram 702illustrated in FIG. 14 is an example, and that other types of operationsmay also be employed.

The operation flow 2702 shown in FIG. 34 can be implemented by softwarestored in a memory of controller 1008. Thus, controller 1008 can beprogrammed to control the sequence of operation based on signalsreceived from the outputs of 3-axis accelerometer circuit 1010. Whencontroller 1008 receives information from outputs X-VOUT 1038 and Y-VOUT1036 of the accelerometer circuit 1010, controller 1008 may change itssequence of execution based on such information.

Controller 1008 may also be programmed to control the flow of electricalpower through lamp module 2128 based on signals received from theoutputs of accelerometer circuit 1010. When controller 1008 receivesinformation from X-VOUT 1038 and Y-VOUT 1036, controller 1008 may changesome of its output signals based on the execution of software stored inthe controller 1008.

Other types of movements of flashlight 2300 that may cause a change inthe outputs of the accelerometer circuit 1010 may also be used as acommand for flashlight 2300 to change features. Accordingly, the currentinvention is not limited to the movements described herein forinterfacing with controller 1008.

FIG. 35 is a flow diagram illustrating a method 1110 for operatingflashlight 2300 in a night light mode of operation. The method 1110shown in FIG. 35 for operating flashlight 2300 in a night light mode ofoperation is shown in more detail than that provided in FIG. 34. Step902 thus corresponds to step 2718 in FIG. 34 when the night light modeis selected. When flashlight 2300 enters the night light mode in step902, the controller 1008 is preferably configured so that the lightsource of flashlight 2300 initially provides light at a constantbrightness.

After flashlight 2300 enters the night light mode in step 902, in step912 the controller 1008 may be programmed to output a command to loadswitch 1006, audio interface & speaker 518, and/or vibrator 520 toprovide a visual, audio, and/or tactile cue that the night light modehas been selected and entered. This cue provided in step 912 isbeneficial because, in the absence of such a cue in the presentembodiment, there would be no immediate operational change in thebrightness of the light source before the timer is expired at step 1908.Thus, providing a visual, audio, or tactile cue in step 912 will informthe user of the selection of the night light mode and make the use ofthe flashlight 2300 more user friendly.

The visual cue may be a simple flash of the light off and then back on.Alternatively, it could be a series of two or more flashes. To providean audio cue in step 1912, either in addition to the visual cue or inthe alternative, the controller 1008 may be programmed to output acertain sequence of beeps or provide beeps of different tones throughthe audio interface & speaker 518 (see FIG. 32), which is incommunication with controller 1008. A tactile cue on the other hand maybe provided through the vibrator 520 (see FIG. 32), which is incommunication with controller 1008.

Once the visual audio or tactile cue is performed in step 1912, a timermay be reset and started in step 1904. The timer is used to determinethe period of time before the flashlight begins to dim. Preferably eachtime a bump of a predefined magnitude is sensed by controller 1008 basedon one or more inputs from accelerometer 1010, the timer is reset, sothat the timer is only allowed to expire, and the brightness of thelight source 101 dim, if the flashlight 2300 remains still for apredefined default period of time, such as 15 or 30 seconds, after thenight light mode is entered in step 902. Thus, as long as the flashlightcontinues to be moved around with sufficient force to cause a requisitechange in acceleration, the flashlight 2300 will not dim.

In certain embodiments, it may be desirable to allow a user to addadditional time to the timer, thereby extending the amount of timerequired to pass in step 1908 without the controller 1008 sensing anacceleration of sufficient magnitude to dim the brightness of the lightsource 101 in step 1916. In the embodiment shown in FIG. 32, controller1008 is programmed to permit the user to adjust the timer. In theillustrated embodiment, the user can adjust the timer if he or she doesnot release the momentary switch once the night light mode is entered instep 902. On the other hand, once the user releases the momentaryswitch, he or she can no longer adjust the timer.

In a preferred embodiment, the timer is set initially to expire in aperiod of 30 seconds in step 1904. If the momentary switch 168 isreleased any time after entering the night light mode without adjustingthe timer, then controller 1008 will simply wait for the timer to expireafter the default period of time lapses in step 1908 before dimming thebrightness of the light source 101 in step 1916. However, as notedabove, preferably the timer is reset each time controller 1008 sensesthat flashlight 2300 is moved with sufficient force. It goes to step1908 to let timer expired.

On the other hand, if the controller determines in step 2720 that themomentary switch 168 has not been released, then the user can adjust thedefault period of time of the timer, thereby delaying the time periodthat must lapse without movement before the brightness of the lightsource 101 is dimmed in step 1916. For example, in the illustratedembodiment, if in step 2724 the controller 1008 determines that theflashlight 2300 has been rotated left or right about its principal axisof projection 310 while momentary switch 168 has been continuouslydepressed, the amount of rotation can be calculated by controller 1008and the timer 1906 adjusted based on the amount of rotation. The timermay be incrementally increased, by for example 15 or 30 seconds, eachtime flashlight 2300 is rotated left or right and then rotated back tocenter. In other words, if additional wait time is desired, steps 2724,1906 can be repeated as long as it is determined that the momentaryswitch remains depressed in step 2728.

Once the timer has been increased by the desired amount, the user mayrelease the momentary switch. When the release of the momentary switchis detected in step 2728, the timer will begin to run until it isdetermined in step 1908 that it has expired. As before, preferably thetimer is reset (now to the adjusted timer preset) each time a force ofsufficient amount is detected so that the timer is permitted to expireonly if the flashlight remains still (or relatively still) for theadjusted time period.

Although the timer is preferably only adjusted by a relatively smallperiod of 15 to 30 seconds for each left or right rotation, the timermay be incrementally increased by any amount in step 1906, including forexample by periods of 1 minute or 5 minutes.

As an alternative to adjusting the timer in step 1906 by an incrementalamount for each time that that flashlight is rotated left or right, thetimer adjustment performed in step 1906 can also be performed based onthe amount of rotation of flashlight 2300. For example, the timer may beincreased by 15 seconds if the flashlight is rotated by at least 15° andless than 30°, and increased by 30 seconds if the flashlight 2300 isrotated left or right by 30° or more. In other implementations othertimes or angles may be used. For example, the timer may be increased byan extra five minutes when flashlight 2300 is rotated left or right byat least 15° and less than 30° and the timer may be increased by anextra ten minutes when flashlight 2300 is rotated left or right for 30°or more.

In another implementation, a visual, audio, or tactile cue is providedwhen the timer is increased in step 1906. Preferably the cue correspondsto the amount of time added to the timer or the adjusted period of timeof the timer, so that the user knows by how much the timer has beenincreased.

Once the timer expires in step 1908, the brightness of the light source101 of flashlight 2300 may be decreased in step 1916. In the presentembodiment, light source 101 of flashlight 2300 may be gradually dimmeduntil reaching its lowest brightness. In another embodiment, lightsource 101 of flashlight 2300 may be gradually dimmed until eventuallyit is completely off.

Once flashlight 2300 has been dimmed in step 1916, it may continuouslyprovide the lowest (or other pre-set) brightness until flashlight 2300detects a bump in step 1918, at which point the brightness of flashlight2300 may be increased 1920 to the brightness level stored memory. In thepresent embodiment, the brightness of light source 101 of flashlight2300 is set to the brightness level that had previously been stored inmemory by the user from the dim mode. In other embodiments, however, thebrightness light source 101 of flashlight 2300 may simply be adjusted toits highest brightness level. Once the brightness has been increased instep 1920, the timer is reset in step 1910 to the adjusted time periodthe timer had been adjusted to in step 1906, or the default time period.The routine then goes back to step 2720 and then to step 1908 where thecontroller 1008 monitors whether the reset timer has expired. Again,preferably the timer is reset each time a movement of a sufficientmagnitude is detected so that the brightness of the light source 101 offlashlight 2300 is only dimmed if the flashlight 2300 remains still oris not moved sufficiently quickly.

As previously described in connection with FIGS. 32 and 33D,accelerometer circuit 1010 has outputs that may also be coupled tocontroller circuit 1008. The accelerometer circuit 1010 may be mountedon circuit board 2348 with its Z-axis extending along the longitudinalaxis of flashlight 2300. When flashlight 2300 is in a horizontalposition, if flashlight 2300 is rotated clockwise or counterclockwiseabout its longitudinal axis 310, the magnitudes of the acceleration inthe X and Y axes may change, and the gravity information on X and Y maybe sent to controller 1008 through X-VOUT 1038 and Y-VOUT 1036,respectively. Controller 1008 may use information from X-VOUT 1038 andY-VOUT 1036 to determine whether there is a rotation about thelongitudinal axis 310 of flashlight 2300. When flashlight 2300 is in ahorizontal position, if flashlight 2300 is tilted up about 45°, themagnitude of the acceleration in the Z axis will change, and the gravityinformation on Z may be sent to controller 1008 through Z-VOUT 1034.Controller 1008 may use information from Z-VOUT 1034 to determinewhether there is a tilting up of flashlight 2300 and where extra waittime is required. Flashlight 2300 may detect a bump or rolling (or theinformation change on X-VOUT 1038 and Y-VOUT 1036) and use thisinformation to determine whether flashlight 2300 should remain as anight light.

The brightness on lamp module 2128 may be determined by changing theduty cycle on lamp module 2128 to a frequency above which a human eyemay detect. A duty cycle on lamp module 2128 may be produced by asequence of high and low states on the LOAD_ENABLE 1044 signal which isdriven by controller 1008. This sequence of high and low states onsignal LOAD_ENABLE 1044, together with other components on the loadelectrical path, may cause NMOS 1054 to be conductive and non-conductivealternately. When the percentage of conduction time in each cycle is at100%, lamp module 2128 will be at its brightest. On the other hand, asthe percentage of conduction time in each cycle approaches 0%, lampmodule 2128 will be at its lowest brightness.

The operation flow 900 shown in FIG. 35 may be implemented by softwarestored in a memory of controller 1008. Controller 1008 may be programmedto control the sequence of operation based on signals received fromoutputs of accelerometer circuit 1010. When controller 1008 receiveinformation from X-VOUT 1038 and Y-VOUT 1036 of the accelerometercircuit 1010, controller 1008 may change its sequence of execution basedon the information.

Controller 1008 may also be programmed to control the flow of electricalpower through lamp module 2128 based on signals received from outputs ofaccelerometer circuit 1010. When controller 1008 receives informationfrom X-VOUT 1038 and Y-VOUT 1036, controller 1008 may change some of itsoutput signals based on the execution of software stored in controller1008.

FIGS. 36A and 36B illustrate flow diagrams 1145, 1162 of a lock outfeature of flashlight 2300. After flashlight 2300 is turned off 1146,the switch 168 might be accidentally pushed under certain conditions,such as movements of the flashlight 2300 stored in a purse, a glove box,or a tool box. The accidental push on switch 168 might turn onflashlight 2300 and power would lost.

The lock out feature 1145, 1162 would prevent accidental turn-on offlashlight 2300 by performing a sequence of operations for flashlight2300 to enter into a lock out mode. Once flashlight 300 is in the lockout mode, all subsequent presses on switch 168 would be ignored untilanother sequence of operations are performed to unlock flashlight 2300.

The lock out feature 1145 starts at step 1146. If flashlight 2300 isturned on when the principal axis of projection 310 is pointed up in asubstantially vertical direction 1148, followed by pointed down in asubstantially vertical direction while switch 168 is continuouslydepressed 1150, flashlight 2300 interprets the sequence as a command tolock out. Once the switch 168 is released 1152, in the presentembodiment, flashlight 2300 acknowledges the lock out command 1154 andenters into the lock out mode 1156. The operation of entering lock outmode 1145 is then complete 1158. While in another embodiment, once theswitch 168 is released 1152, flashlight 2300 may directly enter into thelock out mode 1156 without acknowledging the lock out command 1154.

In the present embodiment, flashlight 2300 acknowledges the lock outcommand 1154 by making a blink. Alternatively, flashlight 2300 mayacknowledge the lock out command 1154 by providing audible or tactileresponses in addition to the visual response or in the alternative.

Once flashlight 2300 is locked out 1156, the only way to exit the lockout mode is through an operation of exiting lock out mode 1162. Theoperation 1162 starts at step 1160. If the principal axis of projection310 is pointed up in a substantially vertical direction followed bypointed down in a substantially vertical direction 1164 while switch 168is continuously depressed 1166, flashlight 2300 interprets the sequenceas a command to exit the lock out mode. Once the switch 168 is released1168, flashlight 2300 is released (or unlocked) from lock out 1170. Inthe present embodiment, flashlight 2300 acknowledges the unlock status1172 and that completes the exiting lock out mode operation 1162 at step1174. In another embodiment, once flashlight 2300 is released (orunlocked) from lock out 1170, the operation of exiting lock out mode1162 is completed without performing the step of acknowledging theunlock status 1172. In one embodiment, once the operation of exitinglock out mode 1162 is completed 1174, flashlight 2300 is subsequentlyturned on. Once flashlight 2300 is locked out 1156, before flashlight2300 receives the unlock command, flashlight 2300 cannot be switched onby a press and release sequence on switch 168.

In the present embodiment, flashlight 2300 acknowledges the unlockcommand 1172 by making a blink. Alternatively, flashlight 2300 mayacknowledge the lock out command 1172 by providing audible or tactileresponses in addition to the visual response or in the alternative.

Alternatively, other types of movements of flashlight 2300 that maycause a change in outputs X-VOUT 1038 and Y-VOUT 1036 or Z-VOUT 1034 ofaccelerometer circuit 1010 may also be used as a command for flashlight2300 to enter or exit the lock out mode.

FIG. 37 is a flow diagram illustrating another lock out feature 1176 offlashlight 2300. The operation starts at step 1190. If flashlight 2300is off 1178, before flashlight 2300 receives the lock out command,flashlight 2300 can be switched on by a switch on command such as apress and release sequence on switch 158, the light source of flashlight2300 may start producing light and the flashlight 2300 may enter into adefault user mode of operation.

If flashlight 2300 is off 1178, and if the switch 168 is pressed andreleased in a sequence of three times 1180, flashlight 2300 interpretsthe sequence as a command to lock out. In the present embodiment,flashlight 2300 acknowledges the lock out command 1182 and enters intothe lock out mode 1184. Alternatively, once flashlight 2300 receives alock out command, flashlight 2300 may directly enter into the lock outmode 1184 without the step of acknowledgement 1182. Once flashlight 2300is locked out 1184, before flashlight 2300 receives the unlock command,flashlight 2300 cannot be switched on by a press and release sequence onswitch 168.

When flashlight 2300 is locked out 1184, if the switch 168 is pressedand released in a sequence of three times 1186, flashlight 2300interprets the sequence as a command to unlock, or release, andflashlight 2300 is subsequently unlocked 1188 and exit lock out mode1192. In one embodiment, once the operation of exiting lock out mode1192 is completed, flashlight 2300 is subsequently turned on.

In the present embodiment, flashlight 2300 acknowledges the lock outcommand 1182 by making a blink. Alternatively, flashlight 2300 mayacknowledge the lock out command 1182 by providing audible or tactileresponses in addition to the visual response or in the alternative.

As previously described in connection with FIG. 33D, accelerometercircuit 1010 may include outputs X-VOUT 1038, Y-VOUT 1036 and Z-VOUT1034 that may be coupled to controller circuit 1008. Accelerometercircuit 1010 may be mounted on circuit board 2348 with its Z-axisextending along the longitudinal axis of the flashlight 2300. Whenflashlight 2300 is pointed up vertically, the magnitude of theacceleration in the Z axis would be −1 G. When flashlight 2300 ispointed down vertically, the magnitude of the acceleration in the Z axiswould be +1 G. The gravity information on Z may be sent to controller1008 through Z-VOUT 1034.

Controller 1008 may use the information on Z-VOUT 1034 to determinewhether flashlight 2300 is pointing up or down to determine whether lockout is desired.

The operation flow diagrams 1145, 1162 shown in FIGS. 36A and 36B may beimplemented by software stored in the memory of controller 1008.Controller 1008 may be programmed to control the sequence of operationbased on signals received from the outputs of accelerometer circuit1010. When controller 1008 receives information from Z-VOUT 1034 ofaccelerometer circuit 1010, controller 1008 may change a user'spreference (or parameter setting) based on this information.

A multi-mode portable electronic lighting device is contemplated. Thedevice comprises a controller and a user interface. The controller isconfigured to implement a plurality of modes of operation. The userinterface is configured to input commands to the controller. The userinterface can have a position sensitive interface in which commands areinput through at least one predefined position of the portableelectronic lighting device.

A portable lighting device is contemplated. The portable lighting deviceis configured to operate using a portable source of power. The portablelighting device comprises a light source; a main power circuit forelectrically connecting the light source to the portable source ofpower, the main power circuit including an electronic power switchdisposed electrically series with the light source; an inertial sensorfor detecting a plurality of predetermined positions and movements ofthe portable lighting device; and a controller electrically coupled tothe portable source of power. The controller including an output forproviding a control signal for controlling the flow of power through theelectronic power switch and light source in the main power circuit,wherein the controller is configured to control the flow of powerthrough the electronic power switch based on the plurality ofpredetermined positions or the movements of the portable lightingdevice.

A method of controlling a multi-mode portable electronic lighting deviceis contemplated. The method comprises the steps of: determining if theportable lighting device has been positioned in one of a plurality ofpredetermined positions; and entering into a new mode of operation whenone of the plurality of predetermined positions is detected.

While various embodiments of an improved flashlight and its respectivecomponents have been presented in the foregoing disclosure, numerousmodifications, alterations, alternate embodiments, and alternatematerials may be contemplated by those skilled in the art and may beutilized in accomplishing the various aspects of the present invention.For example, the power control circuit and short protection circuitdescribed herein may be employed together in a flashlight or may beseparately employed. Further, the short protection circuit may be usedin rechargeable electronic devices other than flashlights. Thus, it isto be clearly understood that this description is made only by way ofexample and not as a limitation on the scope of the invention as claimedbelow.

What is claimed is:
 1. A flashlight, comprising: a switch; and a lockout feature that is activated by: pointing the flashlight in a firstpreselected direction prior to the flashlight being turned on; turningon the flashlight by depressing a switch on the flashlight; tilting theflashlight in a second preselected direction while continuouslydepressing the switch; and releasing the switch; wherein activation ofthe lock out feature prevents the flashlight from being turned on. 2.The flashlight of claim 1, wherein the first preselected direction isvertically upward.
 3. The flashlight of claim 2, wherein the secondpreselected direction is downward.
 4. The flashlight of claim 1, furthercomprising: an exit lock out feature that is activated by: pointing theflashlight in a third preselected direction before depressing theswitch; depressing the switch and tilting the flashlight in a fourthpreselected direction as the switch is continuously depressed; andreleasing the switch while the flashlight is pointed in the fourthpreselected direction; wherein activation of the exit lock out featureallows the flashlight to be turned on.
 5. The flashlight of claim 4,wherein the third preselected direction is upward.
 6. The flashlight ofclaim 5, wherein the fourth preselected direction is downward.